LLM Perks

Claude Opus 5.5

Anthropic · All Claude models
Free right now Frontier New
VisionCodingTool useLong context

Claude Opus 5.5 is a language model from Anthropic. It is currently free at 1 provider with up to 1M tokens of context. The model understands images, is suited to coding, supports tool calling.

Developer
Anthropic
Context
1M tokens
Type
Text
License
Proprietary
Free since
October 13, 2026

Where to use Claude Opus 5.5 for free

Each row is a separate free endpoint with its own limits.

ProviderContextLimitCard
UnoRouter
claude-opus-5.5:free
1M No-card free models use shared capacity and per-model limits; availability can change. No Open

Quick start

curl https://api.unorouter.com/v1/chat/completions \
  -H "Authorization: Bearer $UNOROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-5.5:free",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Example for UnoRouter. Any OpenAI-compatible client works: Cursor, Cline, OpenCode, Open WebUI.

Benchmarks

Intelligence Index
57.6
Humanity's Last Exam
61.4%
Long context (LCR)
84.7%

Source: Artificial Analysis · Claude Opus 5.5 (Max, Default Fallback)

Similar free models

FAQ

Is Claude Opus 5.5 free?

Yes. As of October 13, 2026, Claude Opus 5.5 is free at UnoRouter. Each provider has its own limits — see the table above.

What is the context window of Claude Opus 5.5?

The largest context among free routes is 1,000,000 tokens. Some providers cap it lower.

How do I call Claude Opus 5.5 via API?

Use any OpenAI-compatible client with base URL https://api.unorouter.com/v1, model ID claude-opus-5.5:free, and a UnoRouter key.

How good is Claude Opus 5.5?

Artificial Analysis Intelligence Index: 57.6. For comparison, the strongest free model in the catalog right now is Claude Opus 5.5.

Is Claude Opus 5.5 open-weight?

No, it is proprietary: access is only through provider APIs.