Claude Sonnet 5.5
Last verified September 29, 2026 · Anthropic pricing ↗$2.00/1M input · $10.00/1M output · 1.0M context · Anthropic
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Alternatives to Claude Sonnet 5.5
Pricing Details
AnthropicLaunched September 28, 2026. Same card as Sonnet 5 on every line: $2.00 input, $2.50 5-minute cache write, $4.00 1-hour cache write, $0.20 cache hit (0.1x), $10.00 output. Batch $1.00/$5.00. No Fast mode. Full 1M context at standard pricing. inference_geo 'us' is 1.1x; Vertex AI US/EU multi-region $2.20/$0.22/$11.00. Max output 128K (300K on Batch with the output-300k-2026-03-24 beta header). Same tokenizer as Sonnet 5. Minimum cacheable prompt 512 tokens (Sonnet 5: 1,024); tool-use system prompt 286 tokens (Sonnet 5: 354). Adaptive thinking on by default; effort low/medium/high/xhigh/max, recalibrated vs Sonnet 5. API default effort HIGH (Claude Code and apps default to medium). thinking: disabled, forced tool_choice and non-default temperature/top_p/top_k return 400. Anthropic claims 'up to 30% less per task' than Sonnet 5, no method published. Artificial Analysis Intelligence Index v4.3.2 (read 2026-09-29), score / cost to run index / per task: low 35.8 / $544 / $0.41; medium 40.7 / $701 / $0.59; high 46.7 / $1,176 / $1.08; xhigh 51.9 / $2,738 / $2.74; max 56.0 / $8,977 / $7.60 (~193k output tokens per task, the highest AA has measured). At max it costs more than Opus 5.5 max ($8,708, score 57.6). Anthropic-reported: Terminal-Bench 4.0 70.6 (max), FrontierCode 1.1 52.1 (xhigh), CursorBench 4.0 55.5, GDPval-AA v2.1 1844, OSWorld 2.1 80.1, SWE-Bench Pro 81.3. Falls back to Sonnet 5 on some cyber requests. Retirement not sooner than September 28, 2027. API ID: claude-sonnet-5-5.
Input / 1M tokens
$2
Output / 1M tokens
$10
Context Window
1.0M
Max Output
128K
Price History
Launched at current price on 2026-09-28. No price changes recorded since.
Frequently Asked Questions
Common questions about Claude Sonnet 5.5 pricing and usage