Could not parse response: small local LLMs cannot emit browser-use action JSON

TL;DR

Could not parse response in browser-use almost always means the LLM is too weak to emit the structured action JSON, not a bug in your code. Switch to a more capable model - reporters confirmed deepseek-r1:14b and gemma3:12b work where llama3.2:1b and qwen2.5:14b failed.

Steps

1. Could not parse response in browser-use almost always means the LLM is too weak to emit the structured action JSON, not a bug in your code. Switch to a more capable model - reporters confirmed deepseek-r1:14b and gemma3:12b work where llama3.2:1b and qwen2.5:14b failed. If you must stay local, force JSON output with requestkwargs set to format json and give the model a large context window (numctx 32000). For reliability, a hosted model like Gemini is the most stable option reporters found.

When to use

You are seeing this: For reliability, a hosted model like Gemini is the most stable option reporters found. Use this skill when you run into "Could not parse response: small local LLMs cannot emit browser-use action JSON".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Issue browser-use/browser-use#442 (closed, 36 comments): running the quickstart with a small local model (llama3.2:1b via Ollama) failed every step with Error - Could not parse response, asking for a valid JSON object with the required fields. Multiple reporters hit the same wall with small local models.

Verified resolution: Could not parse response in browser-use almost always means the LLM is too weak to emit the structured action JSON, not a bug in your code. Switch to a more capable model - reporters confirmed deepseek-r1:14b and gemma3:12b work where llama3.2:1b and qwen2.5:14b failed. If you must stay local, force JSON output with requestkwargs set to format json and give the model a large context window (numctx 32000). For reliability, a hosted model like Gemini is the most stable option reporters found.

Source URL: https://github.com/browser-use/browser-use/issues/442