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Claude 3.5 Sonnet vs Claude Opus 4

A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.

Updated

Claude 3.5 Sonnet specs · Claude Opus 4 specs
Verdict by category
  • PriceClaude 3.5 Sonnet

    Claude 3.5 Sonnet is roughly 5.0× cheaper on output tokens ($15.00 vs $75.00 per 1M).

  • Context windowTie

    Both ship a 200K-token context window.

  • BenchmarksClaude Opus 4

    Claude Opus 4 leads in 1 of 1 shared benchmarks; the biggest gap is on HumanEval (Python coding), where it scores 95.0 vs 92.0.

  • ModalitiesTie

    Both handle text, vision.

  • OpennessTie

    Both are closed-weight, API-only.

It's a genuine coin-flip between Claude 3.5 Sonnet and Claude Opus 4: 1 category wins each, with the rest tied. Claude 3.5 Sonnet is roughly 5.0× cheaper on output tokens ($15.00 vs $75.00 per 1M). Both ship a 200K-token context window.

Claude Opus 4 leads in 1 of 1 shared benchmarks; the biggest gap is on HumanEval (Python coding), where it scores 95.0 vs 92.0. Both target the same set of modalities (text, vision), so the deciding factors are price, context, and raw quality. Both are closed-weight, API-only.

Claude Opus 4 is the newer of the two, released 7 months after Claude 3.5 Sonnet, which usually means a more recent knowledge cutoff and updated safety post-training. Claude 3.5 Sonnet is usually picked for coding llm and code review workloads, while Claude Opus 4 sees more deployments in coding llm and coding agent. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.

Side-by-side specs

SpecClaude 3.5 SonnetClaude Opus 4
ProviderAnthropicAnthropic
ReleasedOct 2024May 2025
Modalitiestext, visiontext, vision
Context window200K tokens200K tokens
Max output,,
Input · 1M$3.00 / 1M tokens$15.00 / 1M tokens
Output · 1M$15.00 / 1M tokens$75.00 / 1M tokens
Knowledge cutoff,2025-03
Open weightsNoNo
API availableYesYes

Pricing at scale

What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.

  • Light usage, 100k in / 50k out per day$31.50 vs $158
  • Heavy usage, 1M in / 500k out per day$315 vs $1,575
  • RAG workload, 5M in / 200k out per day$540 vs $2,700

Light usage, 100k in / 50k out per day: $31.50 vs $158 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $315 vs $1,575 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $540 vs $2,700 per month, model A comes out ahead.

Price calculator

Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.

  • Claude 3.5 Sonnet$1.05
  • Claude Opus 4$5.25

Benchmarks compared

Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.

Claude 3.5 SonnetClaude Opus 4
  • HumanEval92.095.0
  • SWE-bench Verified,72.5
Pick Claude 3.5 Sonnet if

Claude 3.5 Sonnet fits when…

  • Mature and battle-tested
  • Strong code
  • Cost-sensitive workloads, 5.0× cheaper than Claude Opus 4 on output tokens.
Pick Claude Opus 4 if

Claude Opus 4 fits when…

  • Set the SWE-bench bar at launch
  • Excellent for writing and code
  • Strong long-context handling
Don't want either?

Consider Claude Opus 4.7

Anthropic's mid-2026 flagship, ahead on SWE-bench, agent reliability, and writing quality.

See Claude Opus 4.7 specsClaude 3.5 Sonnet vs Claude Opus 4.7Claude Opus 4 vs Claude Opus 4.7

Frequently asked

  • Is Claude 3.5 Sonnet or Claude Opus 4 cheaper?
    Claude 3.5 Sonnet is cheaper at $15.00 / 1M tokens per million output tokens, vs $75.00 / 1M tokens for Claude Opus 4.
  • Which has the larger context window?
    Both Claude 3.5 Sonnet and Claude Opus 4 ship a 200K-token context window.
  • Is Claude 3.5 Sonnet or Claude Opus 4 better for coding?
    Both Claude 3.5 Sonnet and Claude Opus 4 are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.
  • Are either of these models open source?
    Neither model ships open weights, both are accessible only via their respective providers' APIs.
  • When were Claude 3.5 Sonnet and Claude Opus 4 released?
    Claude 3.5 Sonnet was released by Anthropic on 2024-10-22. Claude Opus 4 was released by Anthropic on 2025-05-22.
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