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The Domesday Book ofKWJ · AI

Anthropic · The Long-Context Stretch

Claude 3.5 Sonnet

The model that made Claude the coding default. Coding benchmarks beat GPT-4o at launch.

By C.W. Jameson · Published 19 May 2026 · Last reviewed 19 May 2026

Claude 3.5 Sonnet was released in June 2024 and immediately posted the strongest SWE-bench verified numbers of any model. Operators who had kept Claude as a backup quietly made it primary. The version also introduced the first public computer-use capability in October 2024.

Field signature

Writes code with unusually complete error handling. Rarely leaves TODO stubs.

Specifications

Released2024-06
Context window200,000 tokens
Pricing$3 / $15 per million tokens (historical; superseded by 4.x)
Modalitiestext · image · PDF
LicenseCommercial API only
EraThe Long-Context Stretch

Strengths

  • Coding benchmarks
  • First computer-use integration
  • Refusal quality

Weaknesses

  • Superseded by 4.x generation

Authentication markers

The fingerprints by which Claude 3.5 Sonnet can be identified from its output alone.

TellMeaning
Will mention 'artifacts' in Claude.ai context.Claude 3.5 era.

Notable works

  • SWE-bench verified leader June 2024
  • First Claude computer-use

Market position

$3-$15 per million tokens

Partner offer

Anthropic's Claude family is the model lineage most operators end up on for serious agent work. The free tier remains useful.

Try Claude →

Affiliate link — see disclosure.

Primary sources

  1. [1] Anthropic: Claude 3.5 Sonnet

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