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 SoleAPI default channel price. Input costs 1.95 Credits / M for Claude Sonnet 4.5 and 3 Credits / M for Claude Sonnet 5.5, so Claude Sonnet 4.5 is 35% cheaper. Context windows are 200K and 1M.
Specs side by side
| Item | Claude Sonnet 4.5claude-sonnet-4-5-20250929 | Claude Sonnet 5.5claude-sonnet-5-5 |
|---|---|---|
| Input (prompt) · Credits / M | 1.95≈ $0.294 | 3≈ $0.452 |
| Output (completion) · Credits / M | 9.75≈ $1.47 | 15≈ $2.26 |
| Cache read · Credits / M | 0.195 | 0.3 |
| Context window | 200K | 1M |
| Max output | 64K | 128K |
| 7-day uptime | — | — |
| Latest probe latency | — | — |
| Measured throughput | 5.0 t/s | 81.9 t/s |
| Protocols | Anthropic Messages / Gemini generateContent / OpenAI Responses | Anthropic Messages / OpenAI Responses |
| Sample monthly cost (10M in + 2M out) | 39≈ $5.88 | 60≈ $9.04 |
Prices are the SoleAPI default channel price in Credits (1 Credit = ¥1); green marks the better side. Uptime and latency come from SoleAPI probes; a dash means the model is not probed yet.
Capabilities
FAQ
Which is cheaper, Claude Sonnet 4.5 or Claude Sonnet 5.5?
At the SoleAPI default channel price, Claude Sonnet 4.5 input costs 1.95 Credits / M and Claude Sonnet 5.5 input costs 3 Credits / M, so Claude Sonnet 4.5 is 35% 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. SoleAPI 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?
Their capability flags are identical. Every other capability is either supported by both or by neither; see the capability table above.
More comparisons
One API key for both Claude Sonnet 4.5 and Claude Sonnet 5.5
Free credits on sign-up, pay as you go, no monthly fee.