Claude Opus 5 vs Claude Sonnet 5

Claude Opus 5 (Anthropic) versus Claude Sonnet 5 (Anthropic): API pricing, context window, capabilities and uptime, from the same data as each model page, at the KumoAPI default channel price. Input costs 5 Credits / M for Claude Opus 5 and 2 Credits / M for Claude Sonnet 5, so Claude Sonnet 5 is 60% cheaper. Context windows are 1M and 1M.

Claude Opus 5claude-opus-5
Anthropic
Input (prompt)
5Credits / M
Output (completion)
25Credits / M
1M context · 128K output
Claude Opus 5 details
Claude Sonnet 5claude-sonnet-5
Anthropic
Input (prompt)
2Credits / M
Output (completion)
10Credits / M
1M context · 128K output
Claude Sonnet 5 details
Lower input price
Claude Sonnet 5
60% cheaper

Specs side by side

Item
Claude Opus 5claude-opus-5
Claude Sonnet 5claude-sonnet-5
Input (prompt) · Credits / M52
Output (completion) · Credits / M2510
Cache read · Credits / M0.50.2
Context window1M1M
Max output128K128K
7-day uptime——
Latest probe latency——
Measured throughput——
ProtocolsAnthropic MessagesAnthropic Messages
Sample monthly cost (10M in + 2M out)10040

Prices are the KumoAPI default channel price in Credits (1 Credit = ¥1); green marks the better side. Uptime and latency come from KumoAPI probes; a dash means the model is not probed yet.

Capabilities

CapabilityClaude Opus 5Claude Sonnet 5
Vision
Function Calling
Reasoning
Prompt Caching
Streaming
Response Schema
Audio
Video
File Input
Web Search
Realtime
Session
Media
Multipart Form
Binary Response

FAQ

Which is cheaper, Claude Opus 5 or Claude Sonnet 5?

At the KumoAPI default channel price, Claude Opus 5 input costs 5 Credits / M and Claude Sonnet 5 input costs 2 Credits / M, so Claude Sonnet 5 is 60% cheaper. Output and cache prices are in the specs table above.

Which has the larger context window, Claude Opus 5 or Claude Sonnet 5?

Claude Opus 5 offers 1M tokens, Claude Sonnet 5 offers 1M tokens.

Can I switch between Claude Opus 5 and Claude Sonnet 5 at any time?

Yes. KumoAPI calls every model with the same API key; switching is just changing the model field in the request, and billing is split per model in one console.

How do the capabilities of Claude Opus 5 and Claude Sonnet 5 differ?

Their capability flags are identical. Every other capability is either supported by both or by neither; see the capability table above.

More comparisons

Claude Opus 5 vs Claude Fable 5Claude Opus 5 vs Claude Fable 5.1Claude Opus 5 vs Claude Haiku 4.5Claude Opus 5 vs Claude Opus 4.5Claude Opus 5 vs Claude Opus 4.6Claude Opus 5 vs Claude Opus 4.7Claude Opus 5 vs Claude Opus 4.8Claude Opus 5 vs Claude Sonnet 4.5Claude Sonnet 5 vs Claude Fable 5Claude Sonnet 5 vs Claude Fable 5.1Claude Sonnet 5 vs Claude Haiku 4.5Claude Sonnet 5 vs Claude Opus 4.5

One API key for both Claude Opus 5 and Claude Sonnet 5

Free credits on sign-up, pay as you go, no monthly fee.

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