Claude Opus 5.5 vs Claude Sonnet 5.5

A side-by-side comparison of Claude Opus 5.5 and Claude Sonnet 5.5: input/output pricing, capabilities and available endpoints, served live from 服务云AI. Both are reachable with the same API key.

Pricing comparison

ItemClaude Opus 5.5Claude Sonnet 5.5
Input (per 1M tokens)$3.6$1.8
Output (per 1M tokens)$18$9
Cache read explicit (per 1M tokens)$0.18$0.18
Cache write 5m (per 1M tokens)$4.5$2.25

Specifications

ItemClaude Opus 5.5Claude Sonnet 5.5
Context window1,000,0001,000,000
Max output128,000128,000

Capability comparison

ItemClaude Opus 5.5Claude Sonnet 5.5
function_callingYesYes
prompt_cachingYesYes
visionYesYes

Which should you pick

Which is cheaper, Claude Opus 5.5 or Claude Sonnet 5.5?

On input, Claude Sonnet 5.5 is cheaper ($3.6 vs $1.8 per 1M tokens). On output, Claude Sonnet 5.5 is cheaper ($18 vs $9 per 1M tokens). All prices are per million tokens in USD.

What can Claude Opus 5.5 do that Claude Sonnet 5.5 cannot?

both support function_calling, prompt_caching, vision.

Can I switch between Claude Opus 5.5 and Claude Sonnet 5.5 without changing my code?

Yes. Both are available on 服务云AI through one API key and the same OpenAI-compatible endpoint — switching means changing the model field from "claude-opus-5-5" to "claude-sonnet-5-5", nothing else.

Both are available on 服务云AI under one API key — switching between them means changing the model field and nothing else, so you can use each where it fits rather than picking one.

Claude Opus 5.5 · Claude Sonnet 5.5 · All models