Model comparison

Claude Sonnet 5 vs Gemini 3.6 Flash

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

Catalog record checked September 5, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

Anthropic

Claude Sonnet 5

Balanced

Google

Gemini 3.6 Flash

Balanced

AI model capability comparison
Specification	Claude Sonnet 5	Gemini 3.6 Flash
Provider	Anthropic	Google
Tier	Balanced	Balanced
Context window	1M	1M
Max output	Winner: 128K	64K
Input / 1M tokens	$2	Winner: $0.75
Output / 1M tokens	$10	Winner: $3.75
Weights	Closed	Closed
Parameters	Not disclosedUnverified	Not disclosedUnverified
Reasoning levels	adaptive	low, medium, high
Modalities	text, image	text, image, video, audio, pdf
API model id	claude-sonnet-5	gemini-3.6-flash
Released	June 30, 2026	July 21, 2026
Artificial Analysis Intelligence Index (2026-08-14)	Winner: 55	54
Terminal-Bench 2.1 (2026-06-30)	Winner: 80.4	78
Humanity's Last Exam (2026-06-30)	Winner: 57.4	51.2
SWE-bench Verified (2026-09-01)	79.6	Not verifiedUnverified
LiveBench (2026-09-05)	76	Not verifiedUnverified
DeepSWE 1.1 (2026-07)	Not verifiedUnverified	48.6

Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

2026-09-05: LiveBench official leaderboard (benchmark-owned), xhigh effortContamination-resistant general capability across reasoning, coding, math, data analysis, and language, with monthly question refreshes. Comparability: comparable with caveat — Rolling question set: observations months apart measure different question mixes. Record the measurement date and compare within ~1 month windows.
2026-09-01: vals.ai SWE-bench Verified leaderboard (independent, mini-swe-agent bash-only); not published by Anthropic; a 72.7 CosmicJS claim is unverifiedReal GitHub issue resolution: does the model's patch pass the hidden tests. Comparability: comparable with caveat — Post-audit vendor claims and pre-audit scores sit on different task trust levels; scaffolding (agent harness, compute budget) also dominates results. Never aggregate across scaffolds.
2026-08-14: Artificial AnalysisComposite index blending reasoning, knowledge, and coding evals into one 0–100 score. Comparability: directly comparable — AA occasionally rebaselines the index scale between snapshots — a score captured on one date is only comparable to same-snapshot scores (check measuredAt).
2026-08: Google DeepMind model evaluation report (vendor, HLE-Verified full set)Frontier-knowledge ceiling: extremely hard multi-domain questions written to be near-impossible without deep expertise. Comparability: comparable with caveat — Subset/tool configurations (text-only vs with-tools) differ between vendors and materially change scores; must match configuration to compare.
2026-07: Google DeepMind model evaluation report (vendor, quoting Datacurve leaderboard; 3.7 report shows 49 — rounding conflict preserved)Agentic terminal work: multi-step tasks executed in a sandboxed shell environment. Comparability: comparable with caveat — Scores across Terminal-Bench major versions (v1 vs v2) are NOT comparable; harness configuration (container, time limits) also shifts results.
2026-06-30: Anthropic announcement (vendor, with tools)Frontier-knowledge ceiling: extremely hard multi-domain questions written to be near-impossible without deep expertise. Comparability: comparable with caveat — Subset/tool configurations (text-only vs with-tools) differ between vendors and materially change scores; must match configuration to compare.
2026-06-30: Anthropic announcement table (vendor, default effort; via Vellum transcription)Agentic terminal work: multi-step tasks executed in a sandboxed shell environment. Comparability: comparable with caveat — Scores across Terminal-Bench major versions (v1 vs v2) are NOT comparable; harness configuration (container, time limits) also shifts results.

Pricing tiers: Claude Sonnet 5: Standard $2/$10 per MTok; cache reads 10% of base input. Knowledge cutoff Jan 2026. · Gemini 3.6 Flash: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input.

BalancedRecord checked September 3, 2026

Claude Sonnet 5

Claude Sonnet 5 is Anthropic's best speed/intelligence balance for high-volume agentic work at $2/$10.

Best for

Everyday generation
High-volume agents
Cost-sensitive work

Watch out

A step below Opus 5 on the hardest tasks; pick Opus when quality is paramount.

BalancedRecord checked September 5, 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

Superseded by 3.7 Flash on quality; still a solid mid-tier.

When the cheaper one wins

Gemini 3.6 Flash is cheaper on output at $3.75 per million tokens against $10 for Claude Sonnet 5 — about 2.7×. 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. These are standard-tier API rates, excluding batch and cache discounts.

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Evidence confidence: High

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.
3 shared named benchmarks with differing scores — Measured on: Artificial Analysis Intelligence Index, Terminal-Bench 2.1, Humanity's Last Exam.
Verified within the last 90 days — Newest catalog check was 6 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.

Claude Sonnet 5: Anthropic — Claude Sonnet 5 (accessed 2026-08-29)
Claude Sonnet 5: Anthropic news — Claude Sonnet 5 (accessed 2026-08-29)
Gemini 3.6 Flash: Google — Gemini 3.6 Flash (accessed 2026-08-29)
Gemini 3.6 Flash: Google Cloud Gemini pricing (accessed 2026-08-29)

Related comparisons

Diving deeper on one model? Claude Sonnet 5 · Gemini 3.6 Flash

Common questions

Claude Sonnet 5 vs Gemini 3.6 Flash

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

Is Claude Sonnet 5 or Gemini 3.6 Flash cheaper for input?

Gemini 3.6 Flash is cheaper at $0.75 per million input tokens, against $2 for Claude Sonnet 5 — roughly 2.7× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Claude Sonnet 5 has tiered pricing: Standard $2/$10 per MTok; cache reads 10% of base input. Knowledge cutoff Jan 2026. Gemini 3.6 Flash has tiered pricing: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input.

Is Claude Sonnet 5 or Gemini 3.6 Flash cheaper for output?

Gemini 3.6 Flash is cheaper at $3.75 per million output tokens, against $10 for Claude Sonnet 5 — roughly 2.7× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Claude Sonnet 5 has tiered pricing: Standard $2/$10 per MTok; cache reads 10% of base input. Knowledge cutoff Jan 2026. Gemini 3.6 Flash has tiered pricing: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input.

Which has the larger context window, Claude Sonnet 5 or Gemini 3.6 Flash?

Both accept about 1M tokens of context, so document length will not decide between them.

Do Claude Sonnet 5 and Gemini 3.6 Flash support the same reasoning levels?

Claude Sonnet 5 exposes adaptive, while Gemini 3.6 Flash exposes low, medium, high.

Should I use Claude Sonnet 5 or Gemini 3.6 Flash?

Both sit in the balanced tier, so the choice usually comes down to price and context rather than capability. Claude Sonnet 5 suits everyday generation; Gemini 3.6 Flash suits multimodal pipelines.

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 $2 for Claude Sonnet 5 — a 2.7x difference at the headline tier.
Measured capability: Claude Sonnet 5 leads Artificial Analysis Intelligence Index 55 to 54 (measured 2026-08-14).

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