Which AI does what, exactly?
Everyone mentions ChatGPT, Claude, Gemini, open source, agents… and almost nobody explains what any of it means. This is your plain-English guide: no benchmarks, no jargon, no assumption that you’ve been following the AI industry for years.
“I spent a solid three years confused about which AI I was supposed to be using. Turns out the answer is: it depends. But now at least I can tell you what it depends on.”
The Big Names (Frontier Models)
The most powerful and widely-used AI tools: the ones your friends, family, and the news are almost certainly talking about. Made by large companies, mostly with free tiers. If you're just starting out, this is where most people begin.
Not sure what ‘frontier model’ or ‘AI agent’ means? Kevin has a plain-English glossary. →
The tool that started the conversation, and still one of the best for almost anything you ask it to do.
Free tier available · Paid plans for more usage.
No — proprietary (OpenAI keeps this to themselves)
Particularly strong at reading long documents, explaining things clearly, and tasks that need careful reasoning.
Free tier available · Paid plan for more usage.
No — proprietary
Google's AI. Works across Search, Docs, and Gmail, and genuinely useful if you're already in the Google ecosystem.
Free tier available · Advanced plan via Google One subscription.
No (Gemma — Google's open version — is though)
Built into Windows and Microsoft 365. If you live in Word and Excel, Copilot is already waiting.
Free version built into Windows & Edge · Paid plan for Microsoft 365 integration.
No — proprietary
Real-time access to X. Useful when you need an AI that's actually caught up with today's news.
Free with an X (Twitter) account · Paid plan for more usage.
No — proprietary (built by xAI)
One app, many chatbots. A simple way to try ChatGPT, Claude, and Gemini side by side without juggling separate logins.
Gives you access to many different chatbots — ChatGPT, Claude, Gemini, Grok and more — through one app and one subscription.
Free tier available · Paid plan for heavier use and premium bots.
No — proprietary (made by Quora)
Open Source & Local Models
These models have their code — and often the AI itself — freely available to download. Some can run entirely on your own computer so nothing leaves your machine. They take a bit more effort to set up, but they're free and extremely private.
“The code is public. The AI is often free. For some people, that is the whole point.”
The engine behind many AI apps you've heard of: powerful, open, and free to use without a subscription.
Free — download directly or use via Meta AI.
Yes — fully downloadable and free to use
A lightweight European model that handles writing and summarisation well, without the data concerns of US or Chinese alternatives.
Free to download. Also available as a hosted chatbot.
Yes — and it's a European company, so subject to EU data laws
Surprised the entire AI industry with its reasoning ability, though it routes through Chinese infrastructure, which is worth weighing.
Free.
Yes — ⚠️ built and operated in China. Use caution with sensitive personal information.
Microsoft's compact model, capable enough for most tasks and designed to run on more modest hardware.
Free — specifically designed to run well on less powerful computers.
Yes
Google's free, open model family. The small, downloadable cousin of Gemini, made to run on your own hardware.
Free — open and downloadable.
Yes — open weights, free to download and run
AI Agents & Specialist Tools
These go beyond 'ask a question, get an answer.' AI agents carry out multi-step tasks on your behalf — searching, reading, comparing, and presenting results. You're hearing about these constantly right now because they represent a genuinely new way of working.
“This is the part that surprises people. You stop asking. You start delegating.”
Every answer comes with sources you can click and check — the AI tool that shows its working.
Free tier available · Paid plan for more daily searches.
No — proprietary
Upload your own documents and ask questions about them, like having a researcher read everything for you.
Free.
No
Connects AI to your browser so it can read pages, fill in forms, and complete web tasks on your behalf.
A personal AI agent that lives on your computer and you talk to through apps you already use — WhatsApp, Telegram, Discord. It manages email, calendar, reminders, and background tasks on your behalf, 24/7.
Free — open source. You do need a subscription to an AI model (like Claude or ChatGPT) for it to actually run.
Yes — your data and skills stay on your own computer, not a company's server
⚠️ Requires setup — this is not a click-and-go tool. Very new (launched early 2025). Very popular, very fast-moving.
Give it a complex question, wait a few minutes, and get back a properly sourced report instead of a quick answer.
A research agent that searches dozens of live sources and returns a detailed written report — with every claim clearly sourced. Perplexity's strength has always been showing exactly where information comes from, and that carries through here.
Paid — part of Perplexity Pro subscription.
An open-source deep research agent you can run yourself, with full control over what it reads and how it works.
An open source research agent — similar to Deep Research but free to download and run yourself, with full control over how it works.
Free — open source framework. Technical setup required.
⚠️ Requires technical setup — not a click-and-go tool
Google's research agent: searches the full web, reads multiple sources, and writes you a structured summary.
Google's answer to Deep Research — searches across the web and your connected Google documents, then produces a structured report.
Free tier available · Full access with Gemini Advanced subscription.
Can search your Google Drive and Docs as part of its research — unique to Google's ecosystem
An open-source personal agent that lives on your computer, remembers your work, and reaches you through Telegram, Discord, or Slack.
A personal AI agent that runs on your own computer, keeps a long-term memory of your projects, and reaches you through messaging apps. It can run scheduled tasks, research, and routine jobs on your behalf.
Free — open source. You'll need a subscription to an AI model (like Claude or ChatGPT) for it to run.
Yes — your data and skills stay on your own machine
⚠️ Requires setup — built for confident, technical users. Very new and fast-moving.
Run AI on Your Own Computer
These aren't AI models themselves — they're the apps that let you run open source models locally, entirely on your own machine. Nothing leaves your computer. No subscription, no internet required once set up. The difference between the two is mainly about how comfortable you are with clicking buttons versus typing commands.
“No internet. No company logging your questions. Just you and a very fast computer.”
The friendliest way to run AI on your own computer: a proper app with a simple interface, no commands needed.
A proper desktop app — looks and feels like real software — that lets you browse, download, and chat with local AI models. The most beginner-friendly way to run AI locally. No command line needed.
Open it like any other app, browse a catalogue of models, click download, and start chatting. Has a built-in chat interface that looks a lot like ChatGPT — but everything runs on your machine.
Free for personal use. The models it runs are also free.
Mac, Windows, or Linux. At least 8GB RAM — 16GB recommended. No technical skills required.
For those comfortable with a terminal: run powerful open models locally with complete privacy and no subscription.
A lightweight tool that runs in the background and lets you pull and run AI models with simple typed commands. More technical than LM Studio — but extremely popular, and the engine that OpenClaw runs on top of.
You type a short command and the model downloads and runs. Supports 100+ models including Llama, Mistral, Qwen, Phi-4, and DeepSeek. Pair it with a visual front-end (like LM Studio) if you prefer buttons over commands.
Free — and so are most of the models it runs.
Mac, Windows, or Linux. 8GB RAM minimum. Some comfort with a terminal or command prompt helps — though the basics are very simple.
The lean open-source engine that quietly runs AI models on ordinary computers. Powerful, free, and not for the faint-hearted.
A lightweight, open-source engine for running AI models on everyday computers — even without a high-end graphics card. It's the foundation many friendlier local-AI apps are built on.
Free — open source.
Yes — fully open
Mac, Windows, or Linux. Comfort with a command line helps — most people use it through a friendlier app instead.
A newer way to run AI models fast on Apple Silicon Macs, built to make the most of Mac hardware. Mac-only, and still early.
A local AI runner built specifically for Apple Silicon Macs, using Apple's MLX framework to run models faster and manage memory more efficiently than general-purpose tools.
Free — open source.
Yes
An Apple Silicon Mac (M1 or newer). Mac-only.
Apple's own open-source framework for running AI on Mac hardware. The foundation, more for builders than for browsers.
An open-source framework from Apple for running AI efficiently on Apple Silicon. It's a foundation that other Mac AI tools are built on, aimed at developers more than everyday users.
Free — open source.
Yes — made by Apple
An Apple Silicon Mac. Built for developers.
The internet's library of open AI. Where the world's free models and datasets live, and where much of open AI is shared.
A huge public platform hosting hundreds of thousands of free, open AI models and datasets — the central hub of the open AI world.
Free to browse and download · Paid plans for hosting and heavier compute.
The platform hosts open models; many are fully open
The Global Field
AI is no longer just a Silicon Valley story. China in particular has produced several world-class models that rival — and in some cases lead — the Western field. These come up constantly in tech conversations and news, so it's worth knowing they exist. A note worth making: all three listed here are from Chinese companies. That's worth being aware of when it comes to what data you share with them.
“Worth knowing they exist. Worth knowing where they're from. Worth making that call yourself.”
Alibaba's model, strong in both Chinese and English and one of the most capable widely-used Chinese-origin AI tools.
Many versions are free and open source. Hosted version available via Alibaba Cloud.
Many versions yes — downloadable and free to run. Made by Alibaba, the Chinese e-commerce giant. ⚠️ Use caution with sensitive personal data.
From Moonshot AI. Handles very long documents well, making it useful when other tools hit their context limits.
Free tier on kimi.com · Paid plans for heavier use.
Yes (Kimi K2 series) — downloadable. ⚠️ Chinese company — be mindful of what you share.
A capable Chinese model for both conversation and longer writing tasks, with a growing international user base.
Free to use on their apps · API access available.
M2 series yes — downloadable. ⚠️ Chinese company — worth noting for privacy-conscious users.
This guide is updated quarterly. Tools change fast — if you spot something out of date, let us know.