OpenCode vs Claude Code: same model, same test

OpenCode is a free, open-source AI coding helper that works a lot like Claude Code. So we gave both the same three coding jobs from our secret test. To make it fair, OpenCode used the same AI model as Claude Code: Claude Sonnet 5.5. Both passed every secret check in about the same time. But OpenCode read about 5 times less text per job. We also tried a free model in OpenCode: it passed 183 of 186 checks, but took minutes instead of seconds.

What is OpenCode?

OpenCode is "the open source coding agent", as its GitHub page says. A coding agent is an AI helper that reads your code, changes files and runs tests until a job is done. OpenCode works in the terminal, the text window programmers type commands in, just like Claude Code.

It is made by a company called Anomaly and is open source under the MIT licence. That means anyone may use, change and share it for free. On 10 October 2026, it had about 212,500 stars on GitHub, a sign of how many people follow it.

The big difference with Claude Code: OpenCode works with many AI models, from many companies. Claude Code only uses Anthropic's Claude models.

Our test: same jobs, three setups

We used the three jobs from our private coding test, the same ones as in our Claude Haiku 5.5 test and our Cursor test. The tests in our public test kit are known by now, so these stay secret:

• D. Fix a money reader: code that turns "€ 1.234,56" into cents, with several bugs. 28 secret checks.
• E. Split a restaurant bill: shared dishes and a tip, with cents that must add up exactly. 17 checks.
• F. Read a CSV file: a spreadsheet saved as text, where commas, quotes and line breaks can hide inside a field. 17 checks.

Each tool got the job text and worked on its own. Only after it was done did we run our secret checks. We tested three setups, each job three times:

1. Claude Code with Sonnet 5.5, effort "medium". 2. OpenCode with Sonnet 5.5, through OpenRouter, a service that sells access to many AI models. Same model, different tool. 3. OpenCode with LongCat 2.5 Preview, one of the free models OpenCode offers.

Who did the better job?

With the same model, there was no winner. Claude Code and OpenCode both passed all 186 secret checks with Sonnet 5.5, in every try.

The free model, LongCat 2.5, passed 183 of 186. One CSV try did not finish within our limit of 15 minutes; we checked the code it had written by then. Its misses: "empty fields", "parse "1234,5"", "parse "€ 0,5"".

So in our test, the tool did not change the quality. The model did the work. That matches what we saw in our Cursor vs Claude Code test.

Which one was faster?

With Sonnet 5.5, both tools were equally fast. In the middle, one job took:

• Claude Code + Sonnet 5.5: 36 seconds.
• OpenCode + Sonnet 5.5: 38 seconds.
• OpenCode + LongCat 2.5 (free): 439 seconds, about 7.3 minutes.

The free model was much slower. It also needed more steps per job: about 8 instead of 4. Our Claude Code ran on a Windows PC and OpenCode in a Linux sandbox. But the AI itself runs in the cloud either way, so we think that made little difference.

Same model, far less reading

Here the tools really differed. Every time an AI tool takes a step, it sends the model its instructions, the files and everything done so far. That is counted in tokens, small pieces of text.

With the same model, Claude Code read about 269,000 tokens per job. OpenCode read about 53,000. That is about 5 times less.

What does that cost? OpenRouter charged us $0.09 per job on average for OpenCode with Sonnet 5.5. For Claude Code the same tokens are worth about $0.14 at Anthropic's API prices. You do not pay that per job with a Claude plan, as our Claude Code pricing test explains. But if you pay per use, OpenCode was about 37% cheaper here.

Is OpenCode free?

The tool is free. The AI model usually is not. You can connect OpenCode to a paid service, like we did with OpenRouter, or to OpenCode's own service, called Zen.

Zen also has free models, which work without an account. On 10 October 2026 its price list showed about a dozen free ones. Many are free "for a limited time", so this can change.

Check what happens with your data. For LongCat 2.5, which we used, OpenCode says the provider "does not use your data for model training". For some other free models, like Big Pickle, it says "collected data may be used to improve the model". We picked LongCat for that reason.

Can you use your Claude plan in OpenCode?

This is a common question, and the answer is no. Claude Pro and Max are made for Claude's own apps and Claude Code.

OpenCode's own docs say it plainly: "There are plugins that allow you to use your Claude Pro/Max models with OpenCode. Anthropic explicitly prohibits this." OpenCode removed those plugins in version 1.3.0, it says.

So if you want Claude models in OpenCode, you pay per use: with an Anthropic API key, through OpenRouter, or through Zen. If you already pay for a Claude plan, Claude Code is included.

Which one should you pick?

In our test, both tools did perfect work with the same model. So the choice comes down to how you pay and which models you want:

• You already pay for Claude Pro or Max: Claude Code is included, and it did just as well.
• You pay per use, or want to use many models: OpenCode. With Sonnet 5.5 it passed every check, just as fast, and read far less text.
• You want to pay nothing: OpenCode with a free model. LongCat 2.5 passed 183 of 186 checks in our test, but each job took minutes.

One more tip: whichever tool you use, check its permission settings. We tested what Claude Code's modes do in our skip permissions test.

This was a small test with three short jobs. Bigger projects, other languages and longer work may give other results.

How we checked

On 10 October 2026 we ran 27 coding jobs: 3 jobs, 3 tries, 3 setups. Claude Code ran on our Windows 11 PC with the site owner's Claude plan and a clean setup, without personal settings, Sonnet 5.5 at effort "medium". OpenCode 1.18.35 ran in a Linux sandbox at Vercel, with opencode run --auto, which lets it act without asking. For Sonnet 5.5 it used our OpenRouter key; LongCat 2.5 needed no account. The secret checks never went into the sandbox: we copied the finished code back and checked it on our own PC.

OpenCode's costs are what OpenRouter charged us, as OpenCode reported them. Claude Code's cost is our estimate from its token counts and Anthropic's list prices. Times are from start to finish of each job.

One LongCat job hit our 15-minute limit and was stopped; its score counts the code it had written by then. We read OpenCode's docs, providers page, Zen page and command line docs on the same day. The screenshots are our own captures, cropped only. The charts were made by us. None of the images was made by AI.

Correction, 10 October 2026: our first Claude Code runs also loaded the site owner's own Claude Code settings and add-ons, which added text to every step. We ran Claude Code again with a clean setup, with the same jobs and the same result: all secret checks passed. The tokens read per job went from about 360,000 to about 269,000, and the token value from about $0.25 to about $0.14. The numbers in this article are the new ones.