Claude Opus 4.1
Anthropic is retiring this model on 5 August 2026. After that date it stops answering, so it's not a good choice for new work.
The oldest Opus still available. Retires 5 August 2026.
Private by design
When you use Claude Opus 4.1 in Polymeti, your browser sends the message to Anthropic directly, with your own API key. Nothing passes through a Polymeti server.
- We never see your conversation.
- Your API key is stored in your browser, not on our servers.
- Your chat history lives on your device. Back it up to your own Google Drive if you want it on more than one.
What it can do
-
Context window
200,000 tokens
≈ 150,000 words · about 600 pages
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Max output
32,000 tokens
≈ 24,000 words in a single answer
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Knowledge cutoff
January 2025
its training cutoff
- Reads images you attach
- Uses tools
Modalities
- Text Input and output
- Image Input only
- Audio Not supported
- Video Not supported
Features
- Streaming Supported
- Function calling Supported
- Structured outputs Supported
- Fine-tuning Not supported
Ready to try it?
Polymeti is currently invite-only.
Sign inBring your own API key · Your chats stay in your browser