The 5 Best AI Tools & Agents for Productivity: Reviewed & Ranked (2026)
We tested and ranked the 5 best AI productivity tools and agents for 2026, with verified pricing and who each one is really for.
Posted July 1, 2026

Table of Contents
You already know that AI can be a powerful asset for streamlining workflows and maximizing productivity, both at work and in your personal project queue. But there are dozens of tools out there with hundreds of reviews to comb through. We thought putting together a list of the top five options would help you make a decision a lot faster and one you won’t regret.
This ranked, tested shortlist draws on hands-on use plus what people actually report in the community, where the gap between marketing copy and daily reality tends to surface fast.
Read: How to Become an AI Specialist
How We Ranked These AI Productivity Tools
We scored each tool on five things that actually predict whether it sticks in a daily workflow:
- Does it fit your existing workflows? The best AI tools plug into what you already use, whether that is Gmail, Slack, Google Workspace, or your project management tools, instead of forcing you to relearn how you work.
- Can it take action, not just talk? In 2026, the line that matters is between AI chatbots that answer questions and AI agents that execute multi-step tasks across your apps. We weighted real action heavily.
- How steep is the learning curve? A tool you have to fight is a tool you abandon. We favored apps that deliver value within the first ten minutes.
- Is the pricing honest? We checked every figure against the vendor's own page. Tools that hide the real cost behind credit systems or "contact sales" lose points.
- Who actually trusts it? Reputable companies using a tool at scale is a reasonable proxy for reliability, and so is a body of consistent user reviews rather than a handful of launch-day raves.
We verified all prices and features in June 2026. AI pricing and AI capabilities move monthly, so confirm the current numbers before you buy. This article is informational and not financial advice.
The 5 Best AI Productivity Tools and Agents in 2026
| Rank | Tool | Best for | Free plan | Entry paid plan |
|---|---|---|---|---|
| 1 | Claude | All-purpose AI assistant and agent | Yes | $20/mo (Pro) |
| 2 | ChatGPT | Everyday tasks and breadth | Yes (ads in US) | $20/mo (Plus) |
| 3 | Notion AI | Knowledge and project management | Trial only | $20/user/mo (Business, annual) |
| 4 | Perplexity | AI search engine for research | Yes | $20/mo (Pro) |
| 5 | Julius AI | Data analysis | Yes (15 msgs/mo) | $20/mo (Plus) |
1. Claude - Best All-Purpose AI Assistant and Agent
Claude, built by Anthropic, is the AI assistant we reach for most across writing, analysis, coding, and agentic work. It earns the top spot because it does the widest range of serious work well, and because its agent layer (Claude Cowork and Claude Code) turns it from a chatbot into something that takes action on your files and across your tools.
What it is best for: all-purpose AI assistance, long-form content, building internal tools, and handing off multi-step tasks to an agent.
Pricing (verified June 2026): Free. Pro at $20/month ($17/month billed annually). Max at $100/month and $200/month for higher usage. Team and Enterprise for organizations. The free plan is generous, with web search, memory across conversations, file creation, and MCP connector support. Pro includes Claude Code and Claude Cowork, the desktop agent that handles multi-step work on your files. The two Max tiers add usage headroom, not different features.
How Claude works:
At the simplest level, Claude is a chat interface: ask a question in natural language, get an answer. Where it pulls ahead is in the supporting products that share the same brain. Claude Cowork is an agent that works inside your desktop environment, reading and editing files and running multi-step tasks you describe in plain language. Claude Code is an agentic coding tool that lives in your terminal and can build, edit, and run code with minimal hand-holding. The chat, the document creation, and the agents all draw on the same models, so the quality you get in a quick question carries into the heavier work.
For knowledge workers, the practical pattern looks like this: draft your own first pass, then use Claude to edit, restructure, and pressure-test it. Its AI features shine on content creation that runs long, such as an essay, a report, or a piece of long-form content, where holding the whole thing in context matters. For analysts and operators, Cowork can take a folder of messy inputs and produce a clean deliverable. For anyone building, Claude Code turns an afternoon of fiddly setup into a short conversation. Among the AI agents available in 2026, Claude is the most capable for general knowledge work rather than a single narrow task.
What we like:
The free plan does real work, not just a demo. You get web access, memory across conversations, file creation, and connectors without paying.
Cowork and Code are included in Pro. Several competitors charge extra for an agent layer or a coding tool. Here, both come with the $20 plan.
The writing and long-form reasoning are class-leading. For documents, structured analysis, and anything that rewards a long context window, Claude is consistently strong.
Where it falls short:
You are inside the Anthropic ecosystem. Unlike platforms that let you swap between AI models, Claude runs on Anthropic's own models only.
Heavy agent and coding use can hit session and weekly limits on Pro. If you run Claude Code for hours a day, you will feel the caps and may need a Max plan.
Cowork runs locally on your machine, which is good for privacy but makes sharing workflows across a team less seamless than with some dedicated agent builders.
What users say:
Claude holds a 4.5 out of 5 rating on G2 from well over 100 reviews and the same on Capterra. The recurring praise is for writing quality and coding accuracy. The recurring complaint, echoed across community threads, is usage limits during heavy sessions. That tradeoff is the honest shape of the product: excellent output, metered access.
2. ChatGPT - Best for Everyday Tasks and Breadth
ChatGPT is the most versatile AI assistant on this list and, for many people, the first AI tool they ever used. It does not win on any single dimension the way Claude wins on depth or Perplexity wins on search, but it covers more ground than anything else: writing, coding, image creation, video, voice, data analysis, and a deep bench of app connectors. If you want one AI assistant to take the broadest set of repetitive tasks off your plate, this is it.
What it is best for: a do-everything AI assistant for writing, admin, image generation, and quick data analysis, with the widest feature set of any single tool.
Pricing (verified June 2026): Free (with ads in the US). Go at $8/month. Plus at $20/month. Pro at $100/month and $200/month. Business from $20/seat/month. Enterprise custom. Plus is the tier most professionals want, unlocking the current flagship model, Deep Research, the Sora video tool, the Codex coding agent, and Agent Mode. The free plan now shows ads in the US and caps you to a handful of messages on the flagship model before downgrading.
How ChatGPT works:
You treat ChatGPT like a general-purpose virtual assistant: paste in a document and ask for a summary, ask it to find target keywords, draft product descriptions for a catalog, have it write the HTML for a table of contents, or upload a spreadsheet and ask what the data shows. Its chatbot format is forgiving because you refine by following up. Ask for ten bullet points, then ask it to explain the result more simply, and it builds on the prior turn.
Beyond chat, Plus and higher unlock the parts that make it feel state-of-the-art: Agent Mode for multi-step tasks, the Codex coding agent, Sora for video creation, Deep Research for sourced reports, and native image generation that lets you create images from a prompt with no settings to fiddle with. With 60-plus app connectors, ChatGPT reaches into other tools more broadly than most rivals.
What we like:
Unmatched breadth. Voice, image generation, video creation, a coding agent, agent mode, and deep research in one subscription. No other single tool on this list spans this much.
It is the easiest on-ramp. The interface is familiar to almost everyone, so the learning curve is close to zero.
Strong image creation. ChatGPT's image generation is among the best you can use right now, and it takes corrections well.
Where it falls short:
The free and Go tiers now carry ads in the US, and Go is an awkward middle ground: you pay $8 and still see ads while missing the features that make ChatGPT worth using for real work.
Consumer tiers opt in to your content training by default. If you touch client data or anything under NDA, that alone is a reason to use Business or Enterprise instead.
It is a generalist. For deep research with citations, a dedicated AI search engine is sharper. For serious data analysis, a specialist tool goes further.
What users say:
ChatGPT carries one of the highest review counts of any AI tool, with strong ratings on G2 built on thousands of reviews. The consistent theme from users is that Plus pays for itself within a week for anyone who works with words or code daily. The consistent gripe is message caps on the flagship model during long sessions, which is the same wall-heavy Claude users describe.
3. Notion AI - Best for Knowledge and Project Management
Most tools on this list bolt AI onto a chat box. Notion AI bolts it onto the place your team already keeps its documents, wikis, task management boards, and project timelines, and that context is the whole point. When the AI can see your actual workspace, "summarize this," "find the answer," and "draft this" stop being generic and start being specific to your work. This is where AI helps most: it removes the search-and-stitch busywork between knowing something is written down and finding it. For teams that already run on Notion, this is the AI-powered productivity tool with the least friction because it lives where the work already is.
What it is best for: knowledge management, project management, and turning a workspace full of documents into something you can ask questions of.
Pricing (verified June 2026): Free. Plus at $10/user/month (annual). Business at $20/user/month (annual). Enterprise custom. The important 2026 change: the old standalone AI add-on is gone. Full Notion AI, including the AI agents and the workspace-wide Ask Notion search, now lives in the Business plan. Free and Plus include only a limited AI trial. Custom Agents run on a separate credit system at $10 per 1,000 Notion credits on top of a Business or Enterprise seat.
How Notion AI works:
Notion's building blocks are pages and databases. Notion AI sits on top of them and does three broad jobs. First, it generates and edits: drafting text, autofilling databases, creating page summaries, surfacing important messages and action items from long threads, and assigning owners. Second, it answers questions about your own stored information. This is the feature we use most. Instead of scrolling through wikis, you hit Ask Notion and type "how do I categorize internet costs in my expense report?" or "which teammates are based in the US?" and it answers with links to the source pages. Third, as of recent releases, autonomous AI agents execute multi-step workflows using full workspace context, and you can choose which underlying AI model handles a task or let an Auto mode pick.
That model flexibility is worth calling out. Inside Notion AI, you can route a task to different frontier models or let it choose, which is unusual for a productivity suite and useful when one model is better at writing and another at reasoning.
What we like:
The AI has real context. Because it reads your workspace, Ask Notion surfaces answers buried in old meeting notes or databases that you would otherwise spend ten minutes hunting for.
It consolidates the stack. Docs, wikis, project management, meeting notes, and now AI agents in one central hub mean fewer tools and fewer handoffs, with the AI-powered features available wherever the work lives.
Multi-model access: You are not locked to one provider. You can pick the model that fits the task.
Where it falls short:
Full AI now requires the Business plan. A solo user who wants the AI agents and Ask Notion pays $20/user/month minimum, whereas the feature used to be a cheaper add-on. For a ten-person team, that is $2,400 a year before agent credits.
The Custom Agents credit system adds a variable cost on top of seats, and credits do not roll over. Heavy automation can get expensive in a way that is hard to predict.
Notion databases are not a real operations platform. For wikis and knowledge, they excel. Pushed into CRM or heavy-automation territory, they strain.
What users say:
Notion's scale (north of 100 million users) means a deep, consistent review base. Users love it as a knowledge hub and increasingly as a project management tool with AI layered on. The loudest 2026 complaint is the pricing restructure that moved AI into the costlier tier. If your team already lives in Notion, the value is obvious. If it does not, the per-seat math is the thing to model first.
4. Perplexity - Best AI Search Engine for Research
When the task is research rather than generation, a chatbot is the wrong tool and an AI search engine is the right one. Perplexity is the best of them. It combines a large language model with live web search and, critically, cites its sources, so you can verify what it tells you instead of trusting it blindly. For fact-checking, scoping a topic, and pulling real-world signal from the web, it is the tool we open first.
What it is best for: AI-powered research, fact-checking, and finding sourced answers while you work.
Pricing (verified June 2026): Free. Pro at $20/month ($200/year). Max at $200/month. Education Pro at $10/month for verified students and educators. Enterprise from $40/seat/month. The free tier is genuinely useful, with cited answers and a few Pro searches a day. Pro unlocks unlimited Pro search, frontier AI models from multiple providers, file uploads, and the Comet browser. The Comet AI browser, once gated behind the top tier, is now a free download on every platform.
How Perplexity works:
You ask a question, and Perplexity answers in prose with numbered citations you can click to check the original source. It stays on topic across follow-ups, which makes it feel like a research conversation rather than a series of disconnected searches. On paid plans, you can switch between top models from OpenAI, Anthropic, and Google depending on the question, and the Max tier adds a Model Council feature that runs your query across three frontier models at once and synthesizes where they agree and disagree, useful for high-stakes decisions.
The feature we lean on hardest is its social and web search for real opinions. Pointing Perplexity at community discussions surfaces the unvarnished pain points and workarounds that polished marketing pages never show, which is exactly the kind of real-world insight that makes a research pass worth doing. It is a research tool, not a writing tool: you still take its sourced findings somewhere else to actually write.
What we like:
It cites everything. Verifiable sources are the whole reason to use an AI search engine over a chatbot, and Perplexity does this better than most.
Real-world signal. Its ability to search community discussions and the open web turns up genuine user opinions and problems, not just SEO pages.
Multi-model on paid plans. Switch between frontier AI models, or stress-test an answer across several at once with Model Council.
Where it falls short:
The free plan limits heavy research. Daily caps on the best search mode arrive faster than serious researchers would like.
It does not write or edit for you. Perplexity finds and synthesizes, but you still need another tool to produce the final content.
Privacy optics around the Comet browser have drawn scrutiny, so weigh that before adopting it for sensitive work.
What users say:
Perplexity rates 4.5 out of 5 on G2 across a large review base. Users consistently praise source quality and the Reddit-style search for finding real answers. The common knock is that free-tier limits push you to Pro faster than expected. For anyone whose work depends on accurate research, the $20 Pro plan is an easy call, and the $10 Education Pro tier is a standout for students.
5. Julius AI - Best for Data Analysis
The other four tools can poke at a spreadsheet. Julius AI is built for it. Upload a CSV or Excel file, or connect a database, ask a question in plain English, and get a chart and a clear answer back in seconds, no SQL, Python, or pivot-table wizardry required. For the large population of people who need answers from data but are not data analysts, it closes a real gap, and it is the specialist we would put in a stack alongside a generalist like Claude or ChatGPT.
What it is best for: conversational data analysis, auto-generated charts, and recurring reports for non-technical users who need to analyze data without writing code.
Pricing (verified June 2026): Free (15 messages/month, a preview rather than a working tool). Plus, at $20/month with 250 messages. Pro at $45/month (about $37/month annually) with unlimited messages and live database connectors. Team and Enterprise above that. Students and educators get 50% off, which brings Pro under $25/month. Annual billing saves roughly 15%. The jump from individual plans to the team tier is steep, so budget for it before scaling onto Julius.
How Julius AI works:
You upload your data, then chat with it. Behind the scenes, Julius writes and runs Python or R code to filter, group, average, correlate, and visualize, and you can inspect that code if you want to verify it, though most users never need to. Ask "what's my best-selling product by region" or "show the trend in customer churn over the last 12 months," and you get presentation-ready visuals plus a plain-language explanation you can paste into a report.
Two features push it past novelty. Notebooks let you build a sequence of analysis steps once and rerun it on fresh data, which is a genuine time-saver for anyone producing detailed reports weekly or monthly. And on Pro, live database connectors (Snowflake, BigQuery, PostgreSQL, Google Sheets, and more) mean Julius queries your real data directly rather than a stale export. It even connects to Slack, so a team can request analysis from inside their Slack messages without leaving the channel, which keeps important tasks like the weekly numbers from slipping. The follow-up behavior is what makes it feel like an analyst: ask it to "compare that to last quarter," and it reruns on older data and updates the chart instead of starting over.
What we like:
No code required. It removes the technical barrier between a non-technical user and their own data, which is the entire value proposition.
Notebooks for recurring work. Build a monthly report once, refresh the data, and be done. Hours back every cycle.
Multi-model and warehouse connectors. Different models for different analysis types, and direct connections to live databases on Pro.
Where it falls short:
The free plan is a preview, not a tool. Fifteen messages disappear inside a single real session.
The price jump to team tiers is abrupt, with little in between individual and business pricing.
It is not a replacement for a data team. For bespoke modeling, custom pipelines, or high-stakes financial work, you still need a human analyst.
What users say:
Reviewers who tested Julius hands-on in 2026 consistently rate it the best AI data analysis tool for non-technical business users, with clean visualizations and surprisingly solid forecasting for the price. The honest caveats: the credit and message model makes value harder to judge than it used to be, and ambiguous column names or messy spreadsheets can still trip it up. For a team spending hours a week building reports without a dedicated analyst, it pays for itself fast.
Category Picks: The Best AI Tools for Specific Jobs
The five above are the all-rounders. But the right AI tool depends on the task, and some jobs have a sharper specialization. Here are the best tools by category if your need is narrow.
- AI agents and automation: For building AI agents that take actions across your tech stack with automated workflows, dedicated platforms like Gumloop let you create LLM-agnostic agents and custom workflows that connect to Slack, your CRM, and other apps, often easier to set up across a team than a single vendor's agent.
- Meeting notes: Granola is the meeting notes tool people actually keep using. It captures audio locally (no awkward bot joining the call), blends your own notes with the transcript, and is trusted by teams at companies like Ramp, Brex, and Linear.
- Video creation and editing: Descript edits video by editing the transcript, deleting a sentence in the text, and cutting that section from the video tracks, plus AI studio sound and filler-word removal. For generative video creation, the Sora tool inside ChatGPT and Google's Veo lead.
- Image generation and image creation: ChatGPT's native image generation is the best all-rounder. For the most artistic results, Midjourney. For accurate text inside images, use Ideogram. To edit images on brand at scale, workflow tools like Weavy keep outputs consistent.
- Social media management: For tailoring posts to each channel and brainstorming content, Buffer's AI assistant understands the nuances of each platform without prompting, useful for keeping a brand voice consistent across communication channels. For teams that want to analyze sentiment across replies and mentions, social listening tools apply natural language processing to flag how an audience is reacting.
- AI chatbots head-to-head: Claude and ChatGPT are the two best AI chatbots. Google's Gemini is the pick if you live in Google Workspace and want native Gmail, Google Docs, Google Sheets, and Google Calendar integration.
- Scheduling and organizing tasks: Reclaim and Motion use AI to protect focus time and slot tasks onto your calendar around your meetings and calendar events.
- Universal search across your apps: Tools like Glean and Dropbox Dash provide universal search across all your connected data sources, surfacing actionable insights from files scattered across other apps.
A caution worth heeding: not all popular tools are worth your money. A lot of what gets marketed as AI is really thin AI wrappers around someone else's model, with little added value, and the only tools worth paying for are the ones that do something the underlying model alone does not: take action, hold your context, connect to your data, or fit a specific workflow. The tools above clear that bar.
Read: AI Upskilling: Top Firms, Programs, & Tools for Training Your Workforce
How to Pick the Right AI Productivity Tool for You
Start with the problem, not the tool. The single most common mistake is buying the most popular tool and then hunting for a use. Flip it. Name the repetitive task that eats your week, then pick the tool built for it.
Use the free versions as your trial. Every tool here has a free plan good enough to test the core experience. Run your own real work through it for a few days before paying, and only upgrade to a paid plan when you hit a specific wall.
Match the tool to the job:
- General writing, analysis, and agent work that touch many tasks: Claude or ChatGPT.
- Knowledge, documents, and project management are already run in one place: Notion AI.
- Research and fact-checking with sources you can verify: Perplexity.
- Getting answers and detailed reports out of spreadsheets and databases: Julius AI.
Remember the 70/30 rule. A useful way to think about AI productivity: let AI handle roughly 70% of the repetitive, data-heavy work, and keep the 30% that needs creativity, judgment, and decision-making firmly human. These are tools, not replacements. Their output is only as good as the context and direction you give them, which is why the people who get the most from AI are the ones who already understand the work.
Mind the learning curve and the lock-in. A tool that fits your existing workflows and lets you swap AI models beats a more powerful tool that forces you to rebuild how you work or traps you in one ecosystem.
Read: How to Build an AI Agent From Scratch: The Beginner's Guide
Does AI Actually Make You More Productive?
Yes, but with a condition. AI makes you more productive when you point it at tasks you could already do well yourself, such as summarizing, drafting, organizing tasks, analyzing data, and identifying trends. It becomes counterproductive when you use it to do work you do not understand well enough to check. AI is an amplifier: aim it at your strengths, and it multiplies them. Aim it at your blind spots, and it multiplies the errors, too.
The work smarter, not harder cliché finally has tools behind it. Used well, the AI productivity apps on this list hand back hours every week, on email, on meeting notes, on first drafts, on the spreadsheet you have been dreading. Used badly, they generate a pile of mediocre output you then have to spend time fixing. The difference is entirely in how clearly you can direct them.
Key Takeaways
The single most useful thing to remember from this list is that the right AI tool depends on the job, not the hype. A research question, a spreadsheet, a meeting, and a code refactor each have a different best answer, and no single app wins all four. Match the tool to the task, and you get leverage; reach for the most-hyped name, and you get a subscription you barely use.
Here is how the five shook out. Claude is the best all-purpose AI assistant and agent. ChatGPT wins on breadth and everyday tasks. Notion AI is the pick for knowledge and project management. Perplexity is the best AI search engine for research. And Julius AI is the one to beat for data analysis. The honorable mentions and category picks above cover the narrower jobs that each of these five does not own.
Two things should shape how you start. First, the free versions are now good enough to test every tool on this list before you pay, so treat the free plan as your trial and only move to a paid plan when you hit a specific limit. Second, agents are the real 2026 shift. The jump from AI that answers to AI that does (drafts the email, updates the CRM, runs the analysis) is what separates this year's tools from last year's chatbots, and it is where the biggest productivity gains now live.
Knowing the best AI tools is the first step. Learning to wire them into agents and workflows that run your actual work is the next one, and it is where the real edge is in 2026.
If you want to become an AI builder, Leland's AI Builder Program is a live, cohort-based course that turns knowledge workers into people who ship real agents and automated workflows in 6 to 10 weeks, taught by working operators.
You can also learn from the experts directly. Browse upcoming AI automation and agents events to learn tactics live, or work one-on-one with a vetted AI automation and agents coach who builds this for a living.
See also: Top 10 AI Consultants and Experts
Read next:
- The 5 Best AI Coding Agents: Pros & Cons, Reviews, & Which is Best for You
- The 5 Best AI Tools & Agents for Business: Reviewed & Ranked (2026)
- The 5 Best AI Tools & Agents for Developers: Reviewed & Ranked (2026)
- The 5 Best AI Voice Agents (By Type & Function) [2026]
- The 5 Best AI Newsletters to Subscribe to in 2026
- The 5 Best AI Tools & Agents for Finance: Reviewed & Ranked (2026)
- The 5 Best AI Tools & Agents for Video Editing: Reviewed & Ranked (2026)
- The 5 Best AI Personal Assistants: Reviewed & Ranked (2026)
- Agentic AI vs. AI Agents: Differences & What You Need to Know
FAQs
What are AI productivity tools?
- AI productivity tools are software programs that use artificial intelligence, usually large language models, to help you get more done in less time. They range from AI assistants that write and edit content to project management tools that organize tasks to AI agents that take multi-step actions across your apps. What sets the current generation apart is that they can reason, make decisions, and act on context, not just move data between apps.
What is the best AI productivity tool in 2026?
- There is no single best AI tool. The best one depends on the task. For all-purpose assistance and agent work, Claude leads. For breadth and everyday tasks, ChatGPT. For knowledge and project management, Notion AI. For research, Perplexity. For data analysis, Julius AI. Most people end up using two or three together rather than one.
What is the difference between an AI chatbot and an AI agent?
- An AI chatbot answers questions and generates content in a conversation. An AI agent goes further: it takes action, connecting to your tools and completing multi-step tasks like drafting and sending an email, updating a CRM record, or running an analysis. The shift from chatbots to agents is the defining change in AI productivity in 2026.
Are the free versions of these AI tools good enough?
- For testing, yes, and often for light real use. Claude, ChatGPT, Notion, Perplexity, and Julius AI all offer free plans that let you try the core experience. The free tiers are deliberately limited (on messages, searches, or features) to push regular users toward a paid version, so treat free as your trial and upgrade only when you hit a clear limit.
Do AI productivity tools integrate with Google Workspace, Slack, and Microsoft Teams?
- Increasingly, yes. Many of these tools connect to Gmail, Google Docs, Google Sheets, Google Calendar, Slack, and Microsoft Teams, so the AI works inside your existing workflows rather than as a separate silo. Google's Gemini has the deepest native Google Workspace integration. Notion, Perplexity, Julius, and the major agent platforms offer Slack and other app connectors. Check the specific connectors you need before committing, since availability varies by plan.
How much will AI productivity tools cost in 2026?
- Most sit around $20/month for an individual paid plan, with generous free tiers below and power-user tiers ($100 to $200/month) above. Team and enterprise plans are priced per seat and include admin and security controls. The right question is not the sticker price but whether the time the tool saves justifies its cost, which, for daily users, it usually does within the first month.
Will AI tools replace my job?
- These are tools, not replacements. They handle repetitive tasks and amplify what you already do well, but they still need human judgment, creativity, and verification. The 70/30 rule is a good frame: AI takes the repetitive 70%; you keep the 30% that needs a human. The people who benefit most are the ones who understand their own work well enough to direct the AI and catch its mistakes.















