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Model comparison

Claude Opus 5 vs Gemini 3.6 Flash

Anthropic against Google, compared on context, price, and attributed benchmark results.

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

Anthropic

Claude Opus 5

Frontier

vs

Google

Gemini 3.6 Flash

Balanced

AI model capability comparison
SpecificationClaude Opus 5Gemini 3.6 Flash
ProviderAnthropicGoogle
TierFrontierBalanced
Context window1MWinner: 1.05M
Max outputWinner: 128K66K
Input / 1M tokens$5Winner: $0.75
Output / 1M tokens$25Winner: $3.75
WeightsClosedClosed
ParametersNot verifiedUnverifiedNot verifiedUnverified
Reasoning levelslow, medium, high, xhigh, maxminimal, low, medium, high
Modalitiestext, imagetext, image, video, audio, pdf
API model idclaude-opus-5gemini-3.6-flash
ReleasedJuly 24, 2026July 21, 2026
Humanity's Last Exam · source date Claude Opus 5: 2026-09-0163.6Not verifiedUnverified
Terminal-Bench 2.1 · source date Claude Opus 5: 2026-09-0289.1Not verifiedUnverified
Terminal-Bench 2.1 · source date Gemini 3.6 Flash: 2026-07Not verifiedUnverified78
DeepSWE 1.1 · source date Gemini 3.6 Flash: 2026-08Not verifiedUnverified48.6
HLE-Verified · source date Gemini 3.6 Flash: 2026-08Not verifiedUnverified51.2

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.

Gemini 3.6 Flash: Intro Standard $0.75/$3.75 per MTok through December 31, 2026; $1.50/$7.50 from January 1, 2027. Output includes thinking tokens. Cached input $0.075, rising to $0.15; storage $0.50/MTok-hour, rising to $1. Batch/Flex input/output are $0.375/$1.875, rising to $0.75/$3.75. Priority $1.35/$6.75, rising to $2.70/$13.50. Grounding tools have separate charges and quotas; free-tier limits differ from paid.

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

Gemini 3.6 Flash

Gemini 3.6 Flash is Google's balanced multimodal Flash tier with a 1M-token context.

Best for

  • Multimodal pipelines
  • High-volume processing
  • Video and audio input

Watch out

An earlier Flash model, still listed as stable. Google reports improvements on selected tasks for later releases; that does not establish a quality increase for every workload. Thinking includes minimal through high; computer use is Preview. Intro pricing doubles January 1, 2027.

When the cheaper one wins

Gemini 3.6 Flash is cheaper on output at $3.75 per million tokens against $25 for Claude Opus 5 — about 6.7×. 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, Gemini 3.6 Flash is 46.7% Pass@1 at $4.42/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.

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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 · Gemini 3.6 Flash

Common questions

Claude Opus 5 vs Gemini 3.6 Flash

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

Is Claude Opus 5 or Gemini 3.6 Flash cheaper for input?
Gemini 3.6 Flash is cheaper at $0.75 per million input tokens, against $5 for Claude Opus 5 — roughly 6.7× 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. Gemini 3.6 Flash: Intro Standard $0.75/$3.75 per MTok through December 31, 2026; $1.50/$7.50 from January 1, 2027. Output includes thinking tokens. Cached input $0.075, rising to $0.15; storage $0.50/MTok-hour, rising to $1. Batch/Flex input/output are $0.375/$1.875, rising to $0.75/$3.75. Priority $1.35/$6.75, rising to $2.70/$13.50. Grounding tools have separate charges and quotas; free-tier limits differ from paid.
Is Claude Opus 5 or Gemini 3.6 Flash cheaper for output?
Gemini 3.6 Flash is cheaper at $3.75 per million output tokens, against $25 for Claude Opus 5 — roughly 6.7× 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. Gemini 3.6 Flash: Intro Standard $0.75/$3.75 per MTok through December 31, 2026; $1.50/$7.50 from January 1, 2027. Output includes thinking tokens. Cached input $0.075, rising to $0.15; storage $0.50/MTok-hour, rising to $1. Batch/Flex input/output are $0.375/$1.875, rising to $0.75/$3.75. Priority $1.35/$6.75, rising to $2.70/$13.50. Grounding tools have separate charges and quotas; free-tier limits differ from paid.
Which has the larger context window, Claude Opus 5 or Gemini 3.6 Flash?
Gemini 3.6 Flash accepts 1.05M tokens against 1M for Claude Opus 5. This only matters if you routinely send very long documents or large codebases.
Do Claude Opus 5 and Gemini 3.6 Flash support the same reasoning levels?
Claude Opus 5 exposes low, medium, high, xhigh, max, while Gemini 3.6 Flash exposes minimal, low, medium, high.
Should I use Claude Opus 5 or Gemini 3.6 Flash?
We classify Claude Opus 5 in the frontier tier and Gemini 3.6 Flash 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: Gemini 3.6 Flash costs $0.75 per 1M tokens versus $5 for Claude Opus 5 — a 6.7x difference at the headline tier.
  • Context: Gemini 3.6 Flash takes 1.05M against 1M for Claude Opus 5 — only decisive if your prompts approach the smaller window.
  • Positioning: Claude Opus 5 sits in the frontier tier, Gemini 3.6 Flash in the balanced tier. Compare accuracy, reliability, latency, and cost on representative tasks before choosing.
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