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AnthropicClaude 5 familyLegacyReasoning modelReleased 30 Jun 2026

Claude Sonnet 5

Previous Sonnet. Migrate to claude-sonnet-5-5.

Model idclaude-sonnet-5

Price$2 in, $10 out per 1M tokens

Checked29 September 2026

Knows up to January 2026

1,945events after its cutoff

85 historic, 444 major. 286 days of news.

It launched on 30 June 2026, already missing 147 of them.

Five things it has never heard of

How to call it

7 ways to use Claude Sonnet 5, with the model id each provider expects.

Providers, model ids, endpoints and docs for Claude Sonnet 5
ProviderModel idEndpointDocs
Anthropic API (Claude API) claude-sonnet-5 https://api.anthropic.com/v1/messages platform.claude.com
AWS Bedrock (Messages API / Mantle) anthropic.claude-sonnet-5 platform.claude.com
Google Cloud Vertex AI claude-sonnet-5 platform.claude.com
Microsoft Foundry (Azure) claude-sonnet-5 platform.claude.com
Claude Platform on AWS claude-sonnet-5 platform.claude.com
OpenRouter anthropic/claude-sonnet-5 openrouter.ai
Web app claude.ai

Pricing

Prices for Claude Sonnet 5
Input$2 per 1M tokens
Output$10 per 1M tokens
Cache read$0.20 per 1M tokens

As published: “per 1M tokens (USD); Batch API 50% off”.

Source: platform.claude.com, checked 29 September 2026.

Specs

Input
Text, images and PDF
Output
Text
Context window
1,000,000 tokens
Max output
128,000 tokens
Open weights
No
Licence
Proprietary
Training cutoff
January 2026
Released
30 June 2026
Status
Legacy
Type
Reasoning model

What stands out

What its maker marketed at launch, and what people found later, each with its source.

  • Opus 4.8-level quality at Sonnet price

    Anthropic positioned it at parity with Opus 4.8 on many tasks at $2/$10 per MTok.

    Source: anthropic.com

  • Self-verification

    Early testers reported it checks its own output without prompting and finishes multi-step workflows where earlier Sonnets stopped short.

    Source: anthropic.com

  • Cyber safeguards on by default

    It launched with deliberately reduced exploit-development capability and with cyber safeguards enabled.

    Source: anthropic.com

Four assistants, one scale

Claude Sonnet 5 is added as a fifth row. Each row runs from what the model knows (graphite) through the months between its cutoff and its launch (hatched) to today (pink).

  1. GPT-6 Astra 271 at launch, 1,863 today
  2. Claude Opus 5.5 372 at launch, 1,795 today
  3. Gemini 4 Hydrogen 1,863 at launch, 1,889 today
  4. Grok 4.7 387 at launch, 1,829 today
  5. Claude Sonnet 5 147 at launch, 1,945 today
Show as a table
ModelCutoffReleasedMissing at launchMissing today
GPT-6 AstraApril 20263 September 20262711,863
Claude Opus 5.5June 202622 September 20263721,795
Gemini 4 HydrogenMarch 202612 November 20261,8631,889
Grok 4.7May 202621 September 20263871,829
Claude Sonnet 5January 202630 June 20261471,945

Notes

Superseded by claude-sonnet-5-5. $2/$10 introductory price became permanent (planned increase to $3/$15 cancelled). Retirement not sooner than 2027-06-30.

curl https://api.anthropic.com/v1/messages \
 -H "x-api-key: $ANTHROPIC_API_KEY" -H "anthropic-version: 2023-06-01" -H "content-type: application/json" \
 -d '{"model":"claude-sonnet-5","max_tokens":16000,"messages":[{"role":"user","content":"Hello"}]}'

Sources: