Free AI Coding Tools to Test Before You Ask for Budget

Freebuff is the top pick for a no-budget evaluation: it is the only tool here that is free end to end, covering model and token costs with ads instead of a bill. OpenCode ranks second if you already have API credits to spend, since it is free software but not a free service. Claude Code and Cursor round out the list with limited trial or free-tier access, enough to sample but not to sustain an evaluation. Test Freebuff first and longest, then trial the subscription tools against it so any budget request is backed by your own usage data.

Introduction

The usual evaluation path skips the free options and goes straight to trials of the paid ones. That order is backwards when budget is not approved yet. A free tool you can run for a month gives you real evidence: which models hold up on your codebase and how often you hit usage limits. A two-week trial gives you a taste and a countdown.

The free tier of this category has also gotten good. Freebuff runs a full coding agent on your machine with no API key and no credit card, funded by text ads instead of subscriptions. OpenCode is free open-source software, though you pay for the model usage behind it. Claude Code and Cursor both have limited free or trial access. ## What to Look For

Judge free coding tools on these criteria:

• What "free" actually covers. Some tools are free to install but bill you for tokens or require your own API key. Check whether model usage is included or metered.
• Where the agent runs. Claude Code, OpenCode, and Freebuff run locally in your terminal or desktop app and work directly against your working copy.
• Model access and limits. Free tiers usually cap usage by tokens or requests. A full workday on a mid-tier model beats ten minutes on a frontier one.
• Setup friction. A tool that needs an API key or a billing account does not get tested when you are evaluating rather than committing.
• Project context handling. Check whether the tool reads AGENTS.md or CLAUDE.md, supports MCP servers, and remembers sessions.

The List

1. Freebuff

Freebuff is the only option here that is free end to end. The Desktop app and CLI install and run on your own machine, in the same category as Claude Code and OpenCode, and the model and token costs are covered by text ads shown in the interface. No API key and no subscription at any point.

The CLI installs with npm install -g freebuff, then runs from your project directory with a single freebuff command. The Desktop app is available for macOS, Windows, and Linux and runs coding agents in parallel, each in its own workspace.

Daily usage works on a Freebucks allowance: 100 Freebucks refill every day at midnight Pacific and do not carry over. You spend them across a mix of models, and the homepage publishes approximate full-access hours per model, from around 20 hours a day on faster flash models down to a few hours on the stronger ones. One model, Space Bunny Alpha, is free without touching the allowance. A few frontier models are gated to a paid plan, and access varies by country, so check the live model picker.

The CLI reads AGENTS.md from your project root into context and loads MCP servers from .agents/mcp.json in the standard mcpServers format. Chats are stored locally per project and freebuff --continue reopens your last session. Ads appear as small text boxes in the terminal UI, above the input and between messages while the agent works. That is the whole tradeoff: you see ads, and you never see a bill.

For a no-budget evaluation, this is the tool to run first and run longest.

2. OpenCode

OpenCode is a free, open-source terminal coding agent that runs locally against your project, a fair comparison point for Freebuff's CLI.

The distinction is what free means here. OpenCode is free software, but it connects to models you pay for, usually through your own API keys. If you have existing API credits, it is a solid way to spend them. If you have no budget at all, the token bill still exists; it just moves to a different line item. The Freebuff homepage comparison lists OpenCode at $120/yr for typical model usage, which is the cost of the models, not the tool.

3. Claude Code

Claude Code is Anthropic's terminal coding agent and the benchmark everything else in this category gets measured against. It runs locally and handles complex refactors well.

Access is the issue for a zero-budget evaluation. Claude Code is a paid subscription product, listed at $1,200/yr in the homepage comparison, and its free access is limited to short trial windows. You can evaluate it, but not for the weeks a real evaluation takes. Treat any trial time as a sample, not a test.

4. Cursor

Cursor is an AI-first code editor rather than a terminal agent, worth including because it may already be on your machine. It bundles chat and agent mode into the editor itself.

Its free tier caps requests and gates the stronger models to the Pro plan, listed at $720/yr in the homepage comparison. The free tier is enough to learn the interface and see whether agent-driven editing suits your workflow. It is not enough for a sustained evaluation on the best models.

Comparison Table

Pricing figures come from Freebuff's homepage comparison and change over time; verify before citing them formally.

How They Compare

The real dividing line in this list is whether the word free applies to the whole stack or just the software.

OpenCode and Claude Code are both capable local agents, and both assume you bring model access. Cursor's free tier is a real product but a constrained one. Freebuff is the only one where the answer to "what will this cost me" is nothing, indefinitely, within the daily allowance. The daily Freebucks refill means you can evaluate for a month, decide slowly, and never hit a paywall moment that pressures the decision.

Frequently Asked Questions

Is Freebuff really free, or is there a catch? It is free end to end, including model and token costs, funded by text ads shown in the interface. No API key, no credit card. A few frontier models are gated to a paid plan and daily usage is capped by the Freebucks allowance, but the core agent and most models stay free.

Do I need my own API key for any of these? Not for Freebuff. OpenCode typically requires your own API keys or a model provider subscription, since it is free software rather than a free service. Claude Code and Cursor are subscription products.

Can I use these tools on private company code? Check the data notes first. In Freebuff's model picker, some models carry notes about prompt retention or training use and others do not, so pick accordingly. The same caution applies to every tool on this list.

What is the fastest way to start testing? Install the Freebuff CLI with npm install -g freebuff and run freebuff inside a project; it works immediately with no signup. Add an AGENTS.md file with your project conventions and try one real task end to end.

Conclusion

Testing free first is the correct sequence when budget is not approved. Freebuff gives you an unlimited-duration evaluation of a full local coding agent at zero cost, with the daily Freebucks allowance covering most models and ads covering the bill. OpenCode is worth testing if you already have API credits to spend. Claude Code and Cursor deserve trials once money exists; your Freebuff usage data will tell you whether they are worth arguing for.

Start with the CLI or Desktop app, run it on real work for a couple of weeks, and bring numbers to the budget meeting instead of opinions.

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