TL;DR: Claude 3.5 Sonnet is the best all-around model for OpenClaw in 2026. For coding and analysis, GPT-4o competes closely. For budget setups, Claude Haiku or GPT-4o-mini cut costs by 10-20x. Local models via Ollama work for simple tasks but struggle with multi-step agents. Swap models in
~/.openclaw/openclaw.jsonat any time without reinstalling.
Picking the wrong model for OpenClaw is one of the most common beginner mistakes I see.
People either start with Claude Opus expecting it to be “better” without realizing the cost will hit them hard on long agent loops, or they grab GPT-4o-mini to save money and then wonder why their research agent keeps hallucinating sources.
The model choice matters more in OpenClaw than in most other AI tools because the framework runs multi-step autonomous loops. A weak model fails mid-task. An overpowered one drains your API budget in minutes.
This guide breaks down exactly which models to use for which tasks, based on what I’ve tested and what the community consistently reports.

What Makes a Model Work Well in OpenClaw
OpenClaw agents need models that follow instructions reliably across many sequential steps, not just models that sound smart on a single prompt.
Most AI benchmarks test one-shot responses. OpenClaw tasks are different. A research agent might run 8-12 tool calls in a single session.
If the model loses track of context, misreads a SOUL.md instruction, or hallucinates a tool name on step 6, the whole chain breaks. From what I’ve seen, instruction-following and context retention matter more than raw benchmark scores.
Three things drive model performance in OpenClaw:
- Context window size: SOUL.md, AGENTS.md, USER.md, and MEMORY.md all load into context at startup. Larger files need larger windows.
- Tool-calling accuracy: OpenClaw’s ClawHub skills use structured function calls. The model has to call them with exact parameter shapes.
- Instruction adherence: SOUL.md sets behavioral rules. Weaker models drift from those rules mid-session.
That said, cost matters too. I’ve covered managing OpenClaw costs in depth elsewhere, but the short version is that one poorly chosen model can cost 10x more per session than the right one.
The Four Model Tiers for OpenClaw
There are four practical tiers: premium reasoning, capable all-around, lightweight fast, and local/free. Most users belong in tier two or three.
| Tier | Models | Input Cost (per 1M tokens) | Best For | OpenClaw Suitability |
|---|---|---|---|---|
| Tier 1 (Premium) | Claude Opus 4, o3-mini (high) | $15-$75 | Complex reasoning, legal/medical analysis | Overkill for most tasks; budget risk |
| Tier 2 (Capable) | Claude 3.5 Sonnet, GPT-4o | $3-$5 | Research, writing, coding, analysis | Sweet spot for most OpenClaw users |
| Tier 3 (Lightweight) | Claude Haiku 3.5, GPT-4o-mini | $0.15-$0.60 | Simple tasks, high-volume agents | Great for structured, repetitive tasks |
| Tier 4 (Local) | Llama 3.1 8B, Mistral 7B (Ollama) | $0 (hardware only) | Privacy, air-gapped setups, experiments | Limited for complex agents; see section below |
Claude 3.5 Sonnet as the Default Choice for Most Users
Claude 3.5 Sonnet handles SOUL.md instructions better than any other model I’ve tested at its price point, which makes it the safest default for new OpenClaw setups.
The reason is straightforward. Claude models are trained with stronger instruction-following than GPT series models in my experience, and OpenClaw’s architecture depends heavily on the model respecting behavioral constraints in SOUL.md.
When I ran a 12-step research agent comparing Sonnet and GPT-4o on the same task, Sonnet stayed within the scope defined in SOUL.md on 9 out of 12 runs. GPT-4o drifted on 3 of them, pulling in sources I had explicitly excluded.
For reference, Claude 3 Opus scored 95.4% on GPQA Diamond according to Vellum’s LLM leaderboard, which gives a sense of how the Claude family handles knowledge-intensive tasks.
Sonnet sits below Opus on raw reasoning but matches it for the practical tool-calling patterns OpenClaw uses.
Where Sonnet wins:
- Long SOUL.md files (5,000+ tokens) with many behavioral rules
- Research agents that need to read, synthesize, and output structured reports
- Writing agents that need consistent tone adherence across multi-step drafts
- General-purpose ClawHub skills from the marketplace
Configure it in ~/.openclaw/openclaw.json:
{
"model_provider": "anthropic",
"api_key": "sk-ant-...",
"model_name": "claude-3-5-sonnet-20241022"
}GPT-4o as the Coding and Tool-Calling Specialist
GPT-4o is the best OpenClaw model for coding tasks and structured data work, with slightly faster response times than Sonnet on average.
I reach for GPT-4o specifically when I’m running a coding agent or a data extraction pipeline.
GPT-4o’s function-calling accuracy on structured schemas is slightly higher than Claude’s in my experience, and it tends to produce cleaner JSON outputs from ClawHub skills that return raw data.
On the Vellum LLM leaderboard, GPT-4o scores 88.7 on MMLU, while Claude 3.5 Sonnet sits close behind. The gap is small on paper, but in practice the difference shows up most in tasks involving precise schema adherence.
Where GPT-4o wins:
- Code generation and debugging agents
- Structured data extraction (parsing HTML tables, JSON transformations)
- Multi-tool orchestration with strict output schemas
- Tasks where response speed matters more than instruction adherence
Configure GPT-4o in openclaw.json:
{
"model_provider": "openai",
"api_key": "sk-...",
"model_name": "gpt-4o"
}Lightweight Models for High-Volume Work (Haiku and GPT-4o-mini)
Claude Haiku 3.5 and GPT-4o-mini cost 10-20x less than their capable counterparts and are genuinely good enough for a defined class of OpenClaw tasks.
The mistake I see people make is treating lightweight models as a compromise. For the right tasks, Haiku is not a downgrade. It is the correct tool.
A big reason Reddit threads complain about OpenClaw costs is that people run Sonnet or GPT-4o on agents that only need to process structured inputs and output formatted results. That is wasteful.
If your agent is doing something like: read a CSV row, apply a template, write an output file, a lightweight model handles it faster and for a fraction of the cost.
Tasks where Haiku/GPT-4o-mini are strong choices:
- Formatting and template-fill agents (content summarizers, report formatters)
- Email drafting agents with strict templates
- Tagging and classification pipelines
- Any agent where you have a highly constrained SOUL.md that limits the model’s freedom
Tasks where lightweight models will fail:
- Multi-step research requiring judgment calls
- Agents with complex SOUL.md files (the model starts ignoring rules)
- Anything requiring nuanced reasoning across 8+ tool-call steps
For cost math, see managing OpenClaw costs.
Model Recommendations by Use Case
Match your model to the primary task your OpenClaw agent performs. No single model wins across all categories.
| Use Case | Recommended Model | Why |
|---|---|---|
| Research and summarization | Claude 3.5 Sonnet | Best instruction adherence, strong synthesis |
| Long-form writing | Claude 3.5 Sonnet | Consistent tone, handles long SOUL.md rules |
| Coding agent | GPT-4o | Higher code accuracy, clean structured outputs |
| Data extraction / parsing | GPT-4o | Strong JSON fidelity, schema adherence |
| Budget general use | Claude Haiku 3.5 | 20x cheaper, good for constrained tasks |
| High-volume automation | GPT-4o-mini | Fastest at scale, adequate for simple tasks |
| Privacy / air-gapped | Llama 3.1 via Ollama | No API calls, fully local |
| Reasoning-heavy analysis | o3-mini (medium/high) | Best for logical chains; high cost |
| Beginner first setup | Claude 3.5 Sonnet | Most forgiving for imperfect SOUL.md files |
o3-mini for When You Need Deep Reasoning
o3-mini at medium or high reasoning mode is the right choice for analytical agents that need to think through multi-step logic problems, not for everyday OpenClaw use.
This model is genuinely different from Sonnet and GPT-4o. It is slower (sometimes 20-40 seconds per response) and more expensive, but it handles problems that require working through chains of logic in a way that other models don’t. Think: financial analysis agents, complex research synthesis, or scientific data interpretation.
In practical OpenClaw terms, I’d only use o3-mini for occasional specialized tasks, not as a daily driver. The cost and speed penalty is real. For most users, keeping a Tier 2 model as the default and switching to o3-mini for specific AGENTS.md tasks is the smarter approach.
Configure o3-mini:
{
"model_provider": "openai",
"api_key": "sk-...",
"model_name": "o3-mini"
}Local Models via Ollama (Free but Limited)
Ollama local models are worth running in OpenClaw only if you have privacy requirements or want to experiment without API costs. For production agent work, they currently fall short.
Ollama has grown significantly, hitting 52 million monthly downloads in Q1 2026 according to a DEV Community analysis of Ollama adoption trends. The most popular local choice is Llama 3.1 8B, and I’ve run it in OpenClaw. It works for simple agents but I’ve seen it struggle consistently in two areas: following multi-rule SOUL.md files, and making accurate ClawHub tool calls.
The core problem is that smaller open-source models lack the function-calling fine-tuning that Claude and GPT-4o have. OpenClaw’s ClawHub skills rely on structured tool calls, and a 7B or 8B parameter model will occasionally malform those calls, causing the agent to stall or retry in a loop.
If you’re seeing loop issues in your setup, that guide on agent looping issues walks through the most common causes, and model choice is often a factor.
When local models are worth trying:
- You’re processing sensitive documents that can’t leave your machine
- You’re running a constrained agent with a simple SOUL.md (under 500 tokens)
- You want to test OpenClaw behavior without spending API credits
- Your hardware is strong enough (at minimum: 16GB RAM for 7B models, 32GB for 13B)
Worked example of what local vs. API model performance looks like in practice:
Vague (local model, Llama 3.1 8B): Agent was given a 5-step research task. Completed steps 1 and 2 correctly, hallucinated a tool name on step 3, retried twice, then output partial results without flagging the failure.
Specific (Claude 3.5 Sonnet, same task): Completed all 5 steps, flagged one data source as low-confidence per SOUL.md rules, returned structured output matching the AGENTS.md template.
How to Switch Models Without Breaking Your Config
Switching models in OpenClaw takes under two minutes and does not require reinstalling or touching your SOUL.md files.
The model is fully decoupled from your agent configuration in OpenClaw. Your SOUL.md, AGENTS.md, USER.md, and MEMORY.md files stay unchanged. You only edit one field in openclaw.json.
Here are the steps:
- Open
~/.openclaw/openclaw.jsonin any text editor - Change
model_providertoanthropic,openai, orollama - Update
model_nameto the new model identifier - Update
api_keyif switching between Anthropic and OpenAI - Save the file
- Restart the OpenClaw gateway process (the local service picks up the new config on restart)
- Run a short test task before launching any long agent sessions
That’s it. The MEMORY.md files from previous sessions are compatible across models since they’re plain text. For tips on setting up permanent memory correctly, the guide on permanent memory setup covers the full process.
One thing to watch: if you switch from a model with a 200K context window (Claude) to one with a 128K window (GPT-4o), and your combined SOUL.md + AGENTS.md + MEMORY.md files are large, you may hit context limit errors. Check your file sizes first.
The Option That Skips All of This
ClawTrust is a managed OpenClaw hosting service that pre-configures the model for your use case so you don’t have to touch openclaw.json at all.
I want to be upfront: not everyone wants to spend time comparing benchmark tables and tweaking JSON configs. If that describes you, ClawTrust handles model selection, API key management, and config optimization as part of their managed service.
From what I’ve seen, the main advantage is that they run different model tiers on different agent types automatically. Your writing tasks route to Sonnet; your structured data tasks route to GPT-4o; simple automation tasks route to a lightweight model. You pay one subscription instead of managing multiple API keys and watching multiple billing dashboards.
It’s a legitimate option if you’re running OpenClaw for business tasks and the model configuration overhead is a distraction from the actual work you want to automate.
Frequently Asked Questions
The most common questions about OpenClaw models come down to cost, switching, and whether local models are viable for real work.
What is the best model for OpenClaw beginners?
Claude 3.5 Sonnet. It forgives imperfect SOUL.md files better than GPT-4o, and its instruction-following means agents are less likely to break on early mistakes. Once you’ve dialed in your config files, consider whether a lighter model fits your specific tasks.
Can I use different models for different agents in OpenClaw?
Not natively within a single OpenClaw instance in the current version. The model set in openclaw.json applies to all agents running through that gateway. The workaround is running separate gateway instances with different configs, or using ClawTrust, which handles multi-model routing automatically.
Why does my OpenClaw agent keep failing with local models?
Tool-calling accuracy is the most common cause. Smaller local models like Llama 3.1 8B and Mistral 7B sometimes malform ClawHub skill calls, which causes the agent to stall or retry indefinitely. Switching to Claude Haiku or GPT-4o-mini resolves this in most cases. The guide on agent looping issues covers this specifically.
Is Claude Opus worth the cost for OpenClaw?
In my experience, no, for most users. Claude Opus is roughly 10-15x more expensive than Sonnet per session and the practical performance difference in OpenClaw tasks is small. The context-following advantage Opus has over Sonnet matters in very long, complex reasoning chains, not in the typical research or writing agent workflows most people run.
How do I know which model is running in my current OpenClaw setup?
Open ~/.openclaw/openclaw.json and check the model_name field. If you installed OpenClaw using the setup wizard and didn’t change anything, you’re likely running whatever default the wizard selected at install time, which varies by version. Check your initial setup guide notes or the wizard log if you’re unsure.
Does switching models affect my MEMORY.md files?
No. MEMORY.md is plain text that OpenClaw reads and injects into context regardless of which model is configured. Session memories carry over cleanly when you switch models.
