Claude Sonnet 4.5 vs Claude Sonnet 5.5

Claude Sonnet 4.5 (Anthropic) versus Claude Sonnet 5.5 (Anthropic): API pricing, context window, capabilities and uptime, from the same data as each model page, at the WandAPI default channel price. Input costs 1.8 Credits / M for Claude Sonnet 4.5 and 3.2 Credits / M for Claude Sonnet 5.5, so Claude Sonnet 4.5 is 44% cheaper. Context windows are 200K and 1M.

Claude Sonnet 4.5claude-sonnet-4-5-20250929
Anthropic
Input (prompt)
1.8Credits / M
≈ $0.273
Output (completion)
9Credits / M
≈ $1.36
200K context · 64K output91% off
Claude Sonnet 4.5 details
Claude Sonnet 5.5claude-sonnet-5-5
Anthropic
Input (prompt)
3.2Credits / M
≈ $0.485
Output (completion)
16Credits / M
≈ $2.42
1M context · 128K output76% off
Claude Sonnet 5.5 details
Lower input price
Claude Sonnet 4.5
44% cheaper
Larger context
Claude Sonnet 5.5
200K · 1M
More exclusive capabilities
Claude Sonnet 5.5
Response Schema, File Input, Web Search

Specs side by side

Item
Claude Sonnet 4.5claude-sonnet-4-5-20250929
Claude Sonnet 5.5claude-sonnet-5-5
Input (prompt) · Credits / M1.8≈ $0.2733.2≈ $0.485
Output (completion) · Credits / M9≈ $1.3616≈ $2.42
Cache read · Credits / M0.180.16
Context window200K1M
Max output64K128K
7-day uptime—100.0%
Latest probe latency—3.34 s
Measured throughput——
ProtocolsAnthropic MessagesAnthropic Messages
Sample monthly cost (10M in + 2M out)36≈ $5.4564≈ $9.69

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

Capabilities

CapabilityClaude Sonnet 4.5Claude Sonnet 5.5
Vision
Function Calling
Reasoning
Prompt Caching
Streaming
Response Schema
File Input
Web Search
Audio
Video
Realtime
Session
Media
Multipart Form
Binary Response

FAQ

Which is cheaper, Claude Sonnet 4.5 or Claude Sonnet 5.5?

At the WandAPI default channel price, Claude Sonnet 4.5 input costs 1.8 Credits / M and Claude Sonnet 5.5 input costs 3.2 Credits / M, so Claude Sonnet 4.5 is 44% cheaper. Output and cache prices are in the specs table above.

Which has the larger context window, Claude Sonnet 4.5 or Claude Sonnet 5.5?

Claude Sonnet 4.5 offers 200K tokens, Claude Sonnet 5.5 offers 1M tokens.

Can I switch between Claude Sonnet 4.5 and Claude Sonnet 5.5 at any time?

Yes. WandAPI 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 Sonnet 4.5 and Claude Sonnet 5.5 differ?

Only Claude Sonnet 5.5: Response Schema, File Input, Web Search. Every other capability is either supported by both or by neither; see the capability table above.

More comparisons

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One API key for both Claude Sonnet 4.5 and Claude Sonnet 5.5

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Claude Sonnet 4.5 vs Claude Sonnet 5.5: API Pricing, Context & Capabilities | WandAPI