Updated

A single curved terracotta clay wave with a torn ivory paper edge on a dark background, abstract hero artwork for Claude Sonnet 5

Anthropic

Claude Sonnet 5

Anthropic's most agentic Sonnet at launch, close to Opus 4.8 and able to reply with thinking off.

Chat with Claude Sonnet 5 in Super AgentView pricing

What is Claude Sonnet 5?

Claude Sonnet 5 is a Sonnet model from Anthropic, released on June 30, 2026.

Anthropic called it the most agentic Sonnet yet: it plans, uses tools such as browsers and terminals and works on its own, with performance close to Claude Opus 4.8 at a lower price. It improved on Sonnet 4.6 in reasoning, tool use, coding and knowledge work, and its updated tokenizer can count the same input as up to 1.35 times as many tokens. Anthropic now lists it as a legacy model and recommends Claude Sonnet 5.5, but Sonnet 5 can still run with thinking off.

Provider
Anthropic
Context window
1M tokens
Input
Text, Image
Reasoning
Off to max
Max output
128K tokens
Knowledge cutoff
January 2026
Released
Jun 30, 2026

How Claude Sonnet 5 performs

Published by Anthropic

Results Anthropic reported for Claude Sonnet 5. Each lab runs its own setup, so compare these with other models only inside the same table.

Benchmark results Anthropic published for Claude Sonnet 5
BenchmarkScoreSetting
SWE-bench Pro63.2%
Terminal-Bench 2.180.4%
Humanity's Last Exam43.2%no tools
Humanity's Last Exam57.4%with tools
OSWorld-Verified81.2%

Source: anthropic.com

What you can do with Claude Sonnet 5

  • Thinking can be switched off for instant replies

  • Close to Claude Opus 4.8 at a lower cost, according to Anthropic

  • Plans and uses tools such as browsers and terminals

  • 1M-token context window with image input

How to prompt Claude Sonnet 5

  • Switch thinking off for quick rewrites and ideas; turn it on for planning.
  • Attach reference images so it can describe them in the prompts it writes.
  • If you want Anthropic's newest Sonnet, compare the same prompt on Sonnet 5.5.

Where Claude Sonnet 5 fits best

  • Dependable everyday agent work

  • Fast replies with thinking off

  • Scripts, captions and prompt writing

  • Reviewing images you attach

How Claude Sonnet 5 compares

Claude Sonnet 5 compared with other chat models on Flashloop
ModelLMArena textLMArena codingContext windowReasoning
Claude Sonnet 51462#581520#371M tokensOff to max
Kimi K2.61461#591516#44256K tokensOn or off
GPT-6 Sol1459#621519#381.05M tokensOff to max
DeepSeek V4 Pro1458#641501#791M tokensOff, medium, high, extra high
Grok 4.51466#521514#48500K tokensLow, medium, high

Good to know before you start

  • Anthropic lists it as legacy and points to Claude Sonnet 5.5
  • Its tokenizer can turn the same text into up to 1.35 times the tokens Sonnet 4.6 used
  • Writes the prompts but renders nothing itself; Flashloop's generation models make the images and clips

Start chatting with Claude Sonnet 5

Chat with Claude Sonnet 5 in Super Agent

  1. Select Claude Sonnet 5

    Open Super Agent on Flashloop and choose Claude Sonnet 5 in the model picker.

  2. Enter your prompt

    Ask for what you need: an answer, a plan, or the images and videos you want the agent to make.

  3. Send and keep going

    Send the message. Claude Sonnet 5 answers in Super Agent and runs any generations you asked for.

Questions about Claude Sonnet 5

Can Claude Sonnet 5 reply without thinking?

Yes. In Super Agent you can set reasoning to off, or pick low, medium, high, extra high or max. It starts at low.

How does Claude Sonnet 5 compare with Sonnet 5.5?

Anthropic calls Sonnet 5.5 a clear upgrade that runs more than 30% faster. In Super Agent, Sonnet 5 keeps a thinking-off setting that Sonnet 5.5 doesn't offer.

What context window does Claude Sonnet 5 have?

1M tokens. It accepts text and images.

Is Claude Sonnet 5 still supported?

Anthropic lists it as a legacy model and recommends moving to Sonnet 5.5. You can still pick it in Super Agent's model picker.

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