Skip to main content
AI Choice Engine

Model comparison

Claude Opus 5 vs Claude Sonnet 5

Two Anthropic tiers compared on the figures that decide which one a workload actually needs.

Recorded profile verification October 1, 2026Individual provider fields may changeEvidence confidence: Medium — see receipts below

Anthropic

Claude Opus 5

Frontier

vs

Anthropic

Claude Sonnet 5

Balanced

AI model capability comparison
SpecificationClaude Opus 5Claude Sonnet 5
ProviderAnthropicAnthropic
TierFrontierBalanced
Context window1M1M
Max output128K128K
Input / 1M tokens$5Winner: $2
Output / 1M tokens$25Winner: $10
WeightsClosedClosed
ParametersNot verifiedUnverifiedNot verifiedUnverified
Reasoning levelslow, medium, high, xhigh, maxlow, medium, high, xhigh, max
Modalitiestext, imagetext, image
API model idclaude-opus-5claude-sonnet-5
ReleasedJuly 24, 2026June 30, 2026
Humanity's Last Exam · source date Claude Opus 5: 2026-09-01, Claude Sonnet 5: 2026-06-30 (comparability not verified)63.657.4
Terminal-Bench 2.1 · source date Claude Opus 5: 2026-09-0289.1Not verifiedUnverified
Terminal-Bench 2.1 · source date Claude Sonnet 5: 2026-06-30Not verifiedUnverified80.4
LiveBench · source date Claude Sonnet 5: 2026-09-05Not verifiedUnverified76

Dates beside benchmark scores refer to the linked source’s publication or capture date unless that source explicitly states when it measured the result. A shared URL alone does not establish comparable runs; unverified setups are marked. Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

Pricing tiers

Claude Opus 5: Standard $5/$25 per MTok with no long-context surcharge. Cache reads $0.50; 5-minute writes $6.25 and 1-hour writes $10. Batch $2.50/$12.50. First-party Fast research preview $10/$50, unavailable with Batch. US-only inference adds 10% where supported. Batch 300K output requires output-300k-2026-03-24; standard stays 128K. Knowledge cutoff May 2026; retirement not sooner than July 24, 2027.

Claude Sonnet 5: Standard $2/$10 per MTok with no long-context surcharge. Cache reads $0.20; 5-minute writes $2.50 and 1-hour writes $4. Batch $1/$5. US-only inference adds 10% where supported. Batch supports 300K output with output-300k-2026-03-24; standard stays 128K. Knowledge cutoff Jan 2026; retirement not sooner than June 30, 2027.

FrontierRecord checked October 1, 2026

Claude Opus 5

Claude Opus 5 is Anthropic's July 2026 agentic-coding model, now 'Active (legacy)'. Its successor Opus 5.5 has lower base input/output prices ($4/$20 vs $5/$25 per million tokens); performance depends on the workload and evaluation settings.

Best for

  • Complex agentic coding
  • Enterprise work
  • Long-context analysis

Watch out

Active legacy, superseded by Opus 5.5. Test migration: Opus 5.5 makes adaptive thinking always on, rejects forced tool use and the older computer-use tool, and changes thinking-block/progress behavior. Partner cloud lifecycles and prices can differ.

BalancedRecord checked October 1, 2026

Claude Sonnet 5

Claude Sonnet 5 is Anthropic's previous Sonnet generation for high-volume agentic work at $2/$10.

Best for

  • Everyday generation
  • High-volume agents
  • Cost-sensitive work

Watch out

Active legacy. Sonnet 5.5 launched September 28 at the same token price, with breaking changes to thinking, forced tool use, computer use, advisor choices and progress blocks. Sonnet 5 rejects non-default temperature/top_p/top_k; test the exact target model before switching.

When the cheaper one wins

Claude Sonnet 5 is cheaper on output at $10 per million tokens against $25 for Claude Opus 5 — about 2.5×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. On DeepSWE 1.1, Claude Sonnet 5 is 53.8% Pass@1 at $26.4/task versus Claude Opus 5 at 73.6% / $11.84/task. This compares standard short-context token rates, not total cost per accepted task. Include input, cache, context tiers, schedules, retries and review in your pilot.

Run the model picker

Evidence confidence: Medium

How strong and complete the evidence behind this comparison is — not a prediction of which model is better.

  • Pricing verified on both sides — Input and output rates are verified for both models.
  • 4/5 core specs verified on both sides — Not published for at least one side: parameter count.
  • No directly aligned benchmark setup — No benchmark has matching cited sources, source dates, units, effort and recorded run details on both models.
  • Verified within the last 90 days — Older of the two catalog checks was 25 days ago.
  • Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

Related comparisons

Diving deeper on one model? Claude Opus 5 · Claude Sonnet 5

Common questions

Claude Opus 5 vs Claude Sonnet 5

Answered from the verified figures on this page rather than general guidance.

Is Claude Opus 5 or Claude Sonnet 5 cheaper for input?
Claude Sonnet 5 is cheaper at $2 per million input tokens, against $5 for Claude Opus 5 — roughly 2.5× the price. Estimate both input and output token volume for your workload. These are base rates; Claude Opus 5: Standard $5/$25 per MTok with no long-context surcharge. Cache reads $0.50; 5-minute writes $6.25 and 1-hour writes $10. Batch $2.50/$12.50. First-party Fast research preview $10/$50, unavailable with Batch. US-only inference adds 10% where supported. Batch 300K output requires output-300k-2026-03-24; standard stays 128K. Knowledge cutoff May 2026; retirement not sooner than July 24, 2027. Claude Sonnet 5: Standard $2/$10 per MTok with no long-context surcharge. Cache reads $0.20; 5-minute writes $2.50 and 1-hour writes $4. Batch $1/$5. US-only inference adds 10% where supported. Batch supports 300K output with output-300k-2026-03-24; standard stays 128K. Knowledge cutoff Jan 2026; retirement not sooner than June 30, 2027.
Is Claude Opus 5 or Claude Sonnet 5 cheaper for output?
Claude Sonnet 5 is cheaper at $10 per million output tokens, against $25 for Claude Opus 5 — roughly 2.5× the price. Estimate both input and output token volume for your workload. These are base rates; Claude Opus 5: Standard $5/$25 per MTok with no long-context surcharge. Cache reads $0.50; 5-minute writes $6.25 and 1-hour writes $10. Batch $2.50/$12.50. First-party Fast research preview $10/$50, unavailable with Batch. US-only inference adds 10% where supported. Batch 300K output requires output-300k-2026-03-24; standard stays 128K. Knowledge cutoff May 2026; retirement not sooner than July 24, 2027. Claude Sonnet 5: Standard $2/$10 per MTok with no long-context surcharge. Cache reads $0.20; 5-minute writes $2.50 and 1-hour writes $4. Batch $1/$5. US-only inference adds 10% where supported. Batch supports 300K output with output-300k-2026-03-24; standard stays 128K. Knowledge cutoff Jan 2026; retirement not sooner than June 30, 2027.
Which has the larger context window, Claude Opus 5 or Claude Sonnet 5?
Both accept about 1M tokens of context, so document length will not decide between them.
Do Claude Opus 5 and Claude Sonnet 5 support the same reasoning levels?
Both expose these named effort settings: "low", "medium", "high", "xhigh", "max". The same labels do not guarantee equal compute budgets or behavior across providers. Compare quality, latency and cost on your own tasks.
Should I use Claude Opus 5 or Claude Sonnet 5?
We classify Claude Opus 5 in the frontier tier and Claude Sonnet 5 in the balanced tier. Test whether either meets your accuracy, tool-use and latency requirements before choosing on price.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

  • Input price: Claude Sonnet 5 costs $2 per 1M tokens versus $5 for Claude Opus 5 — a 2.5x difference at the headline tier.
  • Positioning: Claude Opus 5 sits in the frontier tier, Claude Sonnet 5 in the balanced tier. Compare accuracy, reliability, latency, and cost on representative tasks before choosing.
Run the model pickerEstimate stack costAll model comparisons

Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Windsurf, or Lovable? Compare agentic harnesses · Latest releases.