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BenchLM

Claude Sonnet 5 vs Gemini 3.5 Flash

Updated September 29, 2026. Rank says Claude Sonnet 5 is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Decision reading

Claude Sonnet 5 has the higher public score estimate, 66.99 versus 63.42, but the 90% score intervals overlap. Treat that as a lead, not a settled winner. 12 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A
Anthropic logo

Anthropic

66.99/100

Supported · Public rank #23

90% interval 62.7–71.3

Model B
Google logo

Google

63.42/100

Supported · Public rank #37

90% interval 55.8–71.1

Shared results
12
Claude Sonnet 5 only
14
Gemini 3.5 Flash only
15
Like-for-like categories
3 / 8
Supported: Claude Sonnet 5 and Gemini 3.5 FlashHow the comparison works

Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Coding work

    Code generation, repair, and software-engineering tasks

    Claude Sonnet 5

    Claude Sonnet 5 leads on the public coding lane, 59.8 to 52.4, with Supported evidence for both models, although the 90% intervals overlap.

    Confidence: limited
  • Agentic work

    Tool use, computer use, and multi-step task completion

    Claude Sonnet 5

    Claude Sonnet 5 leads on the public agentic lane, 64.6 to 50.5, with Supported evidence for both models, although the 90% intervals overlap.

    Confidence: limited
  • Chat turn cost

    1K fresh input + 500 output tokens

    Gemini 3.5 Flash

    Gemini 3.5 Flash has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
Show secondary and unsupported calls
  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    Gemini 3.5 Flash

    Gemini 3.5 Flash has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
  • Repository review cost

    50K fresh input + 3K output tokens

    Gemini 3.5 Flash

    Gemini 3.5 Flash has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates
  • Long documents

    Prompts that approach the documented context limit

    No clear pick

    The documented context windows are equal.

    Confidence: documented

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

59.8Claude Sonnet 552.4Gemini 3.5 Flash

Like-for-like · BenchAlign v5.7

Claude Sonnet 5 leads the like-for-like coding row, although the 90% intervals overlap.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

Same basis rules as the category table below

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

1 category rests on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.

Bars run 0–100 on each benchmark’s normalized display scale

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign v5.7 lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Agentic

Like-for-like
Claude Sonnet 5
64.6
Supported · #12/117
Gemini 3.5 Flash
50.5
Supported · #38/117
Basis
BenchAlign v5.7 lane · 7 vs 8 public rows
Reading
Claude Sonnet 5 leads · intervals overlap

Coding

Like-for-like
Claude Sonnet 5
59.8
Supported · #19/142
Gemini 3.5 Flash
52.4
Supported · #36/142
Basis
BenchAlign v5.7 lane · 11 vs 7 public rows
Reading
Claude Sonnet 5 leads · intervals overlap

Knowledge

Like-for-like
Claude Sonnet 5
64.5
Supported · #26/168
Gemini 3.5 Flash
64.4
Supported · #27/168
Basis
BenchAlign v5.7 lane · 6 vs 4 public rows
Reading
Practical tie

Multimodal

Directional only
Claude Sonnet 5
78.4
#15/50
Gemini 3.5 Flash
87.8
#6/50
Basis
Provisional lane · 1 vs 2 weighted rows
Reading
Directional only

Reasoning

Not comparable
Claude Sonnet 5
78.7
Unranked · 2 rankable rows
Gemini 3.5 Flash
62.8
#19/27
Basis
Provisional lane · 0 vs 2 weighted rows
Reading
Not comparable

Multilingual

Not comparable
Claude Sonnet 5
Not ranked
Gemini 3.5 Flash
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
Claude Sonnet 5
Not ranked
Gemini 3.5 Flash
84.1
#43/124
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
Claude Sonnet 5
Not ranked
Gemini 3.5 Flash
55.1
Unranked · 2 rankable rows
Basis
Provisional lane · 0 vs 2 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.7) differ from the provisional-lane categories. Unranked scores sit on the provisional lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Supported evidence per lane · bars run 0–100Methodology

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

Claude Sonnet 5
$0.007
Fits in one request
Gemini 3.5 Flash
$0.006
Fits in one request

Gemini 3.5 Flash has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Claude Sonnet 5
$0.13
Fits in one request
Gemini 3.5 Flash
$0.102
Fits in one request

Gemini 3.5 Flash has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

Claude Sonnet 5
$0.18
Fits in one request
Gemini 3.5 Flash
$0.15
Fits in one request

Gemini 3.5 Flash has the lower modeled cost

Costs use the listed standard API rates.

Cached input falls back to the list input rate only where a cached rate is unpublished

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

Claude Sonnet 5

$0.2 per 1M cached input tokens

Claude API pricing

Gemini 3.5 Flash

$0.15 per 1M cached input tokens

Google Gemini API pricing

Provider availability

Claude Sonnet 5

Generally Available · Claude API

Anthropic model overview

Gemini 3.5 Flash

Not sourced

Reasoning profile

Claude Sonnet 5

Reasoning

Gemini 3.5 Flash

Reasoning

Weight access

Claude Sonnet 5

Proprietary

Gemini 3.5 Flash

Proprietary

License

Claude Sonnet 5

Proprietary

Gemini 3.5 Flash

Proprietary

Release date

Claude Sonnet 5

2026-06-30

Gemini 3.5 Flash

2026-05-19

If you already use one of these models

Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
Claude Sonnet 5 has the higher public score estimate, 66.99 versus 63.42, but the 90% score intervals overlap.
Workload cost
Repository review: $0.13 vs $0.102. Cache-heavy agent loop: $0.18 vs $0.15.
Context tradeoff
Both models list 1M.
Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 has the higher public score estimate, 66.99 versus 63.42, but the 90% score intervals overlap. The higher estimate is not a decisive winner because the uncertainty ranges overlap.

Which is better for coding, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 leads the public coding lane, 59.8 to 52.4, with Supported evidence for both models, although the 90% intervals overlap.

Which is better for agentic tasks, Claude Sonnet 5 or Gemini 3.5 Flash?

Claude Sonnet 5 leads the public agentic tasks lane, 64.6 to 50.5, with Supported evidence for both models, although the 90% intervals overlap.

Which costs less, Claude Sonnet 5 or Gemini 3.5 Flash?

For the stated presets, chat costs $0.007 on Claude Sonnet 5 and $0.006 on Gemini 3.5 Flash; repository review costs $0.13 and $0.102; the cache-heavy agent loop costs $0.18 and $0.15. Costs use the listed standard API rates.

Which has the larger context window, Claude Sonnet 5 or Gemini 3.5 Flash?

Both models list the same context window, 1M.

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence41 rows

Agentic

  • Terminal-Bench 3.0

    Claude Sonnet 514.6%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • Terminal-Bench 2.1

    Claude Sonnet 580.4%
    Source
    Gemini 3.5 Flash76.2%
    Source

    Claude Sonnet 5 leads this result

  • BrowseComp

    Claude Sonnet 584.7%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • HLE w/ tools

    Claude Sonnet 557.4%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • OSWorld-Verified

    Claude Sonnet 581.2%
    Source
    Gemini 3.5 Flash78.4%
    Source

    Claude Sonnet 5 leads this result

  • Terminal-Bench 2.1 (Vals)

    Claude Sonnet 574.5%
    Source
    Gemini 3.5 Flash74.2%
    Source

    Claude Sonnet 5 leads this result

  • ApprenticeBench

    Claude Sonnet 516%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • MCP Atlas

    Claude Sonnet 5—
    Gemini 3.5 Flash83.6%
    Source

    Not directly comparable

  • Toolathlon

    Claude Sonnet 5—
    Gemini 3.5 Flash56.5%
    Source

    Not directly comparable

  • Finance Agent v2

    Claude Sonnet 5—
    Gemini 3.5 Flash57.9%
    Source

    Not directly comparable

  • Gert Labs

    Claude Sonnet 5—
    Gemini 3.5 Flash61.85%
    Source

    Not directly comparable

  • ResearchClawBench

    Claude Sonnet 5—
    Gemini 3.5 Flash18.0%
    Source

    Not directly comparable

Coding

  • SWE-bench Verified

    Claude Sonnet 585.2%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • SWE-bench Pro

    Claude Sonnet 563.2%
    Source
    Gemini 3.5 Flash55.1%
    Source

    Claude Sonnet 5 leads this result

  • SWE Multilingual

    Claude Sonnet 578.3%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • SWE Multimodal

    Claude Sonnet 528.1%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • Terminal-Bench 2.1

    Claude Sonnet 580.4%
    Source
    Gemini 3.5 Flash76.2%
    Source

    Claude Sonnet 5 leads this result

  • FrontierCode 1.1 Main

    Claude Sonnet 542.7%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • cursorBench32

    Shared source
    Claude Sonnet 561.5%
    Gemini 3.5 Flash48.8%

    Claude Sonnet 5 leads this result

  • VulcanBench CII v1

    Claude Sonnet 589.2%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • LiveCodeBench (Vals)

    Claude Sonnet 582.4%
    Source
    Gemini 3.5 Flash87.6%
    Source

    Gemini 3.5 Flash leads this result

  • SWE-bench (Vals)

    Claude Sonnet 579.6%
    Source
    Gemini 3.5 Flash78.8%
    Source

    Claude Sonnet 5 leads this result

  • cursorBench40

    Claude Sonnet 534.1%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • Vibe Code Bench

    Claude Sonnet 5—
    Gemini 3.5 Flash48.68%
    Source

    Not directly comparable

  • cursorBench31

    Claude Sonnet 5—
    Gemini 3.5 Flash49.8%
    Source

    Not directly comparable

Reasoning

  • MRCRv2

    Claude Sonnet 5—
    Gemini 3.5 Flash77.3%
    Source

    Not directly comparable

  • MRCR 1M

    Claude Sonnet 5—
    Gemini 3.5 Flash26.6%
    Source

    Not directly comparable

  • ARC-AGI-2

    Claude Sonnet 5—
    Gemini 3.5 Flash72.1%
    Source

    Not directly comparable

Multimodal

  • CharXiv

    Claude Sonnet 588.3%
    Source
    Gemini 3.5 Flash84.2%
    Source

    Claude Sonnet 5 leads this result

  • CharXiv w/o tools

    Claude Sonnet 577%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • MMMU-Pro

    Claude Sonnet 5—
    Gemini 3.5 Flash83.6%
    Source

    Not directly comparable

  • Blueprint-Bench 2

    Claude Sonnet 5—
    Gemini 3.5 Flash33.6%
    Source

    Not directly comparable

Knowledge

  • HLE

    Claude Sonnet 557.4%
    Source
    Gemini 3.5 Flash40.2%
    Source

    Claude Sonnet 5 leads this result

  • HLE w/o tools

    Claude Sonnet 543.2%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • HLE-Verified

    Claude Sonnet 531.0%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • LABBench2

    Claude Sonnet 580.1%
    Source
    Gemini 3.5 Flash—

    Not directly comparable

  • GPQA Diamond (Vals)

    Claude Sonnet 588.9%
    Source
    Gemini 3.5 Flash92.7%
    Source

    Gemini 3.5 Flash leads this result

  • MMLU-Pro (Vals)

    Claude Sonnet 587.5%
    Source
    Gemini 3.5 Flash89.5%
    Source

    Gemini 3.5 Flash leads this result

  • GPQA-D

    Claude Sonnet 5—
    Gemini 3.5 Flash92.7%
    Source

    Not directly comparable

Math

  • FrontierMath v2 (Tiers 1-3)

    Claude Sonnet 5—
    Gemini 3.5 Flash38.966%
    Source

    Not directly comparable

  • FrontierMath v2 (Tier 4)

    Claude Sonnet 5—
    Gemini 3.5 Flash14.583%
    Source

    Not directly comparable

41 public results · 12 shared

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Last updated September 29, 2026