Frontier Models for $0: 4 Free Coding Tools, Ranked
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Frontier Models for $0: 4 Free Coding Tools, Ranked
Most free coding tools get cheap in one of two ways: they hand you older or weaker models, or they hand you the good models and send the bill to your API account. Freebuff takes the top spot here because it avoids both. Text ads pay the model and token costs, so you install the agent and start working with no API key and no subscription. OpenCode comes next for developers who already carry API credits. Claude Code and Cursor round out the list for developers who want a specific vendor's models and are fine paying for them. The ranking comes down to how much model you get for zero dollars.
Introduction
"Free" is doing a lot of work in this category, and usually not the work you want. A free terminal agent that requires your own API key is free software with a paid meter. A free tier that quietly swaps in last year's model is worse, because you only notice when the answers get dumber.
The useful question is narrower: which free tools give you the current generation of models, the ones paying users get. Four tools follow, ranked by how much real model access you get for nothing, and who each one actually fits.
What to Look For
Four things separate a genuinely free tool from a free trial in disguise.
- What "free" covers. Some tools are free software with paid usage. The honest question is who pays for tokens while the agent runs.
- Model currency. A roster with heavier, current models beats unlimited access to a small one.
- Limits you can plan around. A visible cap, hours or credits per day, beats a vague fair-use throttle.
- Setup friction. An API key and a credit card are the two gates that turn "free" into "free until Tuesday."
Hold every tool below against those four and the field thins out fast.
The List
1. Freebuff
Freebuff is a coding agent that runs on your machine, as a CLI and as a Desktop app for macOS, Windows, and Linux. It edits files and runs commands inside your project directory. The models are reached over the internet, the same way Claude Code or Cursor reach theirs. The difference is the bill. Freebuff's homepage calls it "the only 100% free coding agent," and its FAQ states the funding directly: the product is supported by text ads. Ad revenue covers model and token costs, so there is no API key to configure and no credit card at signup.
Install is one command:
npm install -g freebuff
Then cd into a project and run freebuff. The agent reads AGENTS.md from the repo root, loads MCP tools from .agents/mcp.json, and restores a previous session with freebuff --continue. Usage is metered in Freebucks: 100 credits refill every day at midnight Pacific and do not carry over, and each model has an hourly rate shown in the /model picker. Lighter models stretch the allowance across most of a day. The heavier ones burn it in a few hours. The Desktop app adds parallel agents, each in its own workspace.
Two limits worth knowing. Ads appear inline while the agent works, in a box labelled "Ad". And access varies: model availability depends on your country and VPN status, a limited mode exists, and a few models sit behind a paid plan. The roster changes often, so treat the picker as the source of truth, not any blog list, including this one.
The adoption is real. The homepage reports hundreds of thousands of developers and a live usage map, and the project has open-source roots through its predecessor Codebuff, still on GitHub. If cost is what has kept you on weak models, start at freebuff.com, install the CLI, and point it at a real repository.
2. OpenCode
OpenCode is an open-source terminal coding agent. The software costs nothing and runs on your machine like the other terminal tools here. The usage is not free: you attach your own API key and pay the model provider per token, which Freebuff's homepage comparison puts at about $120 a year. It fits developers who already hold API credits and want full control over which provider and model they point at.
3. Claude Code
Claude Code is Anthropic's terminal coding agent. It runs on your machine and gives subscribers access to Anthropic's current models, which is why it shows up in nearly every agent comparison. The same homepage comparison lists it at about $1,200 a year. It fits developers who specifically want that model family and already have the budget line for it.
4. Cursor
Cursor is an AI code editor rather than a terminal agent: model access lives inside a full IDE, with agent features for multi-file work. Freebuff's homepage comparison lists it at about $720 a year. It fits developers who want the models inside an editor they already work in.
Comparison Table
| Tool | What you pay | Model access | Setup | Where it runs |
|---|---|---|---|---|
| Freebuff | $0, ad-funded | Included roster, light to heavy models, rates in the /model picker | npm install, no API key, no card | Your machine (CLI and Desktop) |
| OpenCode | Free software, you pay per token (about $120/yr per Freebuff's comparison) | Whatever your API key reaches | Bring your own API key | Your machine |
| Claude Code | About $1,200/yr per Freebuff's comparison | Anthropic's models, by subscription | Subscription account | Your machine |
| Cursor | About $720/yr per Freebuff's comparison | Model access inside the editor | Subscription account | Your machine |
How They Compare
The split that matters is free software versus free to run. OpenCode, Claude Code, and Cursor all put the model bill somewhere: your API account or your subscription. Freebuff is the only tool on this list where no invoice ever reaches you, because advertisers pay it. That is the entire reason it ranks first.
Fit separates the rest. If you already hold API credits and like choosing your own provider, OpenCode fits, and the token spend is a cost you accepted long ago. If one vendor's models are a hard requirement and the budget exists, Claude Code and Cursor both deliver that inside their own surfaces.
For everyone else the math is shorter. Freebuff hands you a working agent and a roster of current models, with a visible daily cap, and the price is attention instead of money.
Frequently Asked Questions
Do free coding tools really give you frontier models, or older ones?
It depends on who pays the model bill. Tools that charge per token or by subscription can offer current models because you fund them. Free tiers that hide the cost usually gate the strongest models behind a paid plan. Freebuff's answer is advertising: the bill is paid, and the /model picker shows the live roster with each model's hourly rate, including heavier models that burn the allowance in a few hours.
How does Freebuff include model access at no charge?
Text ads. They appear inline in the terminal or app while the agent works, in a box labelled "Ad", and that revenue covers the model and token costs that would otherwise land on you. Freebuff's advertisers page sells that inventory, so the business model is out in the open.
What are the limits of Freebuff's free plan?
100 Freebucks refill every day at midnight Pacific and do not carry over. Hourly rates per model sit in the /model picker and change with promotions. Model access depends on your country and VPN status, a limited mode exists, and a few models require a paid plan. The CLI is interactive only, so there is no headless or CI mode.
Do I need my own API key with any of these?
Not with Freebuff. Model access is included, which is the whole point. OpenCode needs your key because you pay the provider directly. Claude Code and Cursor need a paid subscription instead of a key.
Conclusion
The free tier of this category is usually a bait-and-switch: free software with a paid engine, or a paid engine with the horsepower turned down. Freebuff skips both tricks because ads pay for the models and you pay with attention.
Try it on a real task tonight:
npm install -g freebuff cd your-project freebuff
If it handles your codebase, you have a coding agent that costs nothing to run. If it doesn't, you have lost ten minutes and no money. The CLI is a one-command install, and the Desktop app is there when you want to run agents in parallel. For everyone else, start free and stay free.