Claude Opus 4.5 vs Gemini 3 Flash

Updated September 23, 2026. Rank cannot separate these two. Price, access, and your workload decide. Public scores include evidence status and uncertainty.

Decision reading

Claude Opus 4.5 has the higher public score estimate, 55.9 versus 55.62, but the 90% score intervals overlap. Treat that as a lead, not a settled winner. 5 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

Model A

Claude Opus 4.5

Anthropic

55.9/100

Supported · Public rank #52

90% interval 43.7–68.1

Model B

Gemini 3 Flash

Google

55.62/100

Supported · Public rank #56

90% interval 40.4–70.8

Shared results: 5
Claude Opus 4.5 only: 40
Gemini 3 Flash only: 6
Like-for-like categories: 0 / 8

Supported: Claude Opus 4.5 and Gemini 3 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.

Long documents
Prompts that approach the documented context limit
Gemini 3 Flash
Gemini 3 Flash has the larger documented context window.
Confidence: documented
Chat turn cost
1K fresh input + 500 output tokens
Gemini 3 Flash
Gemini 3 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

Repository review cost
50K fresh input + 3K output tokens
Gemini 3 Flash
Gemini 3 Flash has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.
Confidence: listed-rates
Coding work
Code generation, repair, and software-engineering tasks
Not enough matched evidence
Claude Opus 4.5 is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like.
Confidence: limited
Agentic work
Tool use, computer use, and multi-step task completion
Not enough matched evidence
Claude Opus 4.5 is scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.
Confidence: limited
Cache-heavy agent loop cost
200K cached + 20K fresh input + 10K output tokens
Not enough matched evidence
The page does not recommend a cost winner because at least one model cannot fit the stated workload in one request. Claude Opus 4.5 does not fit this workload in one request. Claude Opus 4.5 has no published cached-input rate, so cached tokens use its listed input rate.
Confidence: rate-fallback

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.

Pick the job you would use them for

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

46.1Claude Opus 4.536.9Gemini 3 Flash

Directional only · BenchAlign v5.6

Claude Opus 4.5 scores higher, but at least one score rests on Estimated evidence or a different benchmark set. Directional only, no winner.

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

Open the coding leaderboard Shortlist models for this job

Same basis rules as the category table below

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.

FrontierMath v2 (Tiers 1-3)Math
Normalized gap 14.9
Claude Opus 4.5:20.690%
Gemini 3 Flash:35.640%
Shared source

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 v5.6 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

Directional only

Claude Opus 4.5: 31.4; Estimated · #64/105
Gemini 3 Flash: 31.4; Supported · #65/105
Basis: BenchAlign v5.6 lane · 15 vs 4 public rows
Reading: Directional only

Coding

Directional only

Claude Opus 4.5: 46.1; Estimated · #48/135
Gemini 3 Flash: 36.9; Supported · #75/135
Basis: BenchAlign v5.6 lane · 5 vs 3 public rows
Reading: Directional only

Knowledge

Directional only

Claude Opus 4.5: 49.0; Estimated · #57/160
Gemini 3 Flash: 52.4; Supported · #46/160
Basis: BenchAlign v5.6 lane · 6 vs 2 public rows
Reading: Directional only

Instruction following

Directional only

Claude Opus 4.5: 30.6; #114/124
Gemini 3 Flash: 64.7; #70/124
Basis: Provisional lane · 1 vs 0 weighted rows
Reading: Directional only

Reasoning

Not comparable

Claude Opus 4.5: 72.1; Unranked · 4 rankable rows
Gemini 3 Flash: 59.0; Unranked · 2 rankable rows
Basis: Provisional lane · 1 vs 0 weighted rows
Reading: Not comparable

Multimodal

Not comparable

Claude Opus 4.5: 23.5; #48/50
Gemini 3 Flash: 75.8; Unranked · 1 rankable row
Basis: Provisional lane · 2 vs 0 weighted rows
Reading: Not comparable

Multilingual

Not comparable

Claude Opus 4.5: 82.9; #2/12
Gemini 3 Flash: Not ranked
Basis: Provisional lane · 1 vs 0 weighted rows
Reading: Not comparable

Math

Not comparable

Claude Opus 4.5: 57.9; #6/7
Gemini 3 Flash: 50.0; Unranked · 2 rankable rows
Basis: Provisional lane · 4 vs 2 weighted rows
Reading: Not comparable

Category scores with the server-provided evidence basis for Claude Opus 4.5 and Gemini 3 Flash
Category	Claude Opus 4.5	Gemini 3 Flash	Basis	Reading
Agentic	31.4Estimated · #64/105	31.4Supported · #65/105	Directional onlyBenchAlign v5.6 lane · 15 vs 4 public rows	Directional only
Coding	46.1Estimated · #48/135	36.9Supported · #75/135	Directional onlyBenchAlign v5.6 lane · 5 vs 3 public rows	Directional only
Knowledge	49.0Estimated · #57/160	52.4Supported · #46/160	Directional onlyBenchAlign v5.6 lane · 6 vs 2 public rows	Directional only
Instruction following	30.6#114/124	64.7#70/124	Directional onlyProvisional lane · 1 vs 0 weighted rows	Directional only
Reasoning	72.1Unranked · 4 rankable rows	59.0Unranked · 2 rankable rows	Not comparableProvisional lane · 1 vs 0 weighted rows	Not comparable
Multimodal	23.5#48/50	75.8Unranked · 1 rankable row	Not comparableProvisional lane · 2 vs 0 weighted rows	Not comparable
Multilingual	82.9#2/12	Not ranked	Not comparableProvisional lane · 1 vs 0 weighted rows	Not comparable
Math	57.9#6/7	50.0Unranked · 2 rankable rows	Not comparableProvisional lane · 4 vs 2 weighted rows	Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign v5.6) 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 Opus 4.5: $0.0175; Fits in one request
Gemini 3 Flash: $0.002; Fits in one request

Gemini 3 Flash has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

Claude Opus 4.5: $0.325; Fits in one request
Gemini 3 Flash: $0.034; Fits in one request

Gemini 3 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 Opus 4.5: $1.35; Does not fit in one request; Cached input priced at the published list-input rate
Gemini 3 Flash: $0.05; Fits in one request

Claude Opus 4.5 does not fit this workload in one request. Claude Opus 4.5 has no published cached-input rate, so cached tokens use its listed input rate.

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.

SpecificationClaude Opus 4.5Gemini 3 Flash

Context window

Maximum documented context; output-token limits may be lower.

Claude Opus 4.5

200K

Gemini 3 Flash

Google Gemini API pricing

API model ID

Claude Opus 4.5

Not sourced

Gemini 3 Flash

gemini-3-flash-preview

Google Gemini API pricing

Cached-input rate

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

Claude Opus 4.5

Not published

Gemini 3 Flash

$0.05 per 1M cached input tokens

Google Gemini API pricing

Documented inputs

Claude Opus 4.5

Not sourced

Gemini 3 Flash

Not sourced

Documented outputs

Claude Opus 4.5

Not sourced

Gemini 3 Flash

Not sourced

Provider availability

Claude Opus 4.5

Not sourced

Gemini 3 Flash

Not sourced

Reasoning profile

Claude Opus 4.5

Non-Reasoning

Gemini 3 Flash

Non-Reasoning

Weight access

Claude Opus 4.5

Proprietary

Gemini 3 Flash

Proprietary

License

Claude Opus 4.5

Proprietary

Gemini 3 Flash

Proprietary

Release date

Claude Opus 4.5

2025-11-01

Gemini 3 Flash

2025-12-01

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 Opus 4.5 has the higher public score estimate, 55.9 versus 55.62, but the 90% score intervals overlap.
Workload cost: Repository review: $0.325 vs $0.034. Cache-heavy agent loop: $1.35 vs $0.05.
Context tradeoff: Gemini 3 Flash has the larger documented window (1M).

Run the same representative tasks against both endpoints before changing production traffic.

Questions

Which is better, Claude Opus 4.5 or Gemini 3 Flash?

Claude Opus 4.5 has the higher public score estimate, 55.9 versus 55.62, 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 Opus 4.5 or Gemini 3 Flash?

Claude Opus 4.5 scores higher for coding on the public lane, 46.1 to 36.9. Claude Opus 4.5 is scored on Estimated evidence for coding, so the reading is directional rather than like-for-like. BenchLM does not name a winner for coding from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which is better for agentic tasks, Claude Opus 4.5 or Gemini 3 Flash?

Claude Opus 4.5 is scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, Claude Opus 4.5 or Gemini 3 Flash?

For the stated presets, chat costs $0.0175 on Claude Opus 4.5 and $0.002 on Gemini 3 Flash; repository review costs $0.325 and $0.034; the cache-heavy agent loop costs $1.35 and $0.05. Claude Opus 4.5 does not fit this workload in one request. Claude Opus 4.5 has no published cached-input rate, so cached tokens use its listed input rate.

Which has the larger context window, Claude Opus 4.5 or Gemini 3 Flash?

Gemini 3 Flash has the larger documented context window: 1M, compared with 200K.

Benchmark evidence

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

Browse raw public benchmark evidence51 rows

Agentic

Terminal-Bench 2.0
Claude Opus 4.559.3%
Source
Gemini 3 Flash—
Not directly comparable
OSWorld-Verified
Claude Opus 4.566.3%
Source
Gemini 3 Flash—
Not directly comparable
OSWorld
Claude Opus 4.566.3%
Source
Gemini 3 Flash—
Not directly comparable
Claw-Eval
Claude Opus 4.559.6%
Source
Gemini 3 Flash49.2%
Source
Claude Opus 4.5 leads this result
QwenClawBench
Claude Opus 4.552.3%
Source
Gemini 3 Flash—
Not directly comparable
τ³-bench results
Claude Opus 4.570.2%
Source
Gemini 3 Flash—
Not directly comparable
VITA-Bench
Claude Opus 4.523.3%
Source
Gemini 3 Flash—
Not directly comparable
DeepPlanning
Claude Opus 4.526.4%
Source
Gemini 3 Flash—
Not directly comparable
Toolathlon
Claude Opus 4.543.5%
Source
Gemini 3 Flash—
Not directly comparable
MCP Atlas
Claude Opus 4.542.3%
Source
Gemini 3 Flash—
Not directly comparable
MCP-Tasks
Claude Opus 4.571.8%
Source
Gemini 3 Flash—
Not directly comparable
WideResearch
Claude Opus 4.576.4%
Source
Gemini 3 Flash—
Not directly comparable
CyberGym
Claude Opus 4.550.6%
Source
Gemini 3 Flash—
Not directly comparable
Gert Labs
Shared source
Claude Opus 4.564.23%
Gemini 3 Flash56.63%
Claude Opus 4.5 leads this result
JobBench
Shared source
Claude Opus 4.532.3%
Gemini 3 Flash11.4%
Claude Opus 4.5 leads this result
Terminal-Bench 2.1 (Vals)
Claude Opus 4.5—
Gemini 3 Flash53.9%
Source
Not directly comparable

Coding

SWE-bench Verified
Claude Opus 4.580.9%
Source
Gemini 3 Flash—
Not directly comparable
LiveCodeBench v6
Claude Opus 4.584.8%
Source
Gemini 3 Flash—
Not directly comparable
SWE-bench Pro
Claude Opus 4.557.1%
Source
Gemini 3 Flash—
Not directly comparable
SWE Multilingual
Claude Opus 4.577.5%
Source
Gemini 3 Flash—
Not directly comparable
NL2Repo
Claude Opus 4.543.2%
Source
Gemini 3 Flash—
Not directly comparable
Vibe Code Bench
Claude Opus 4.5—
Gemini 3 Flash20.20%
Source
Not directly comparable
LiveCodeBench (Vals)
Claude Opus 4.5—
Gemini 3 Flash85.6%
Source
Not directly comparable
SWE-bench (Vals)
Claude Opus 4.5—
Gemini 3 Flash75.0%
Source
Not directly comparable

Reasoning

LongBench v2
Claude Opus 4.564.4%
Source
Gemini 3 Flash—
Not directly comparable
AI-Needle
Claude Opus 4.574%
Source
Gemini 3 Flash—
Not directly comparable

Multimodal

MMMU-Pro
Claude Opus 4.570.6%
Source
Gemini 3 Flash—
Not directly comparable
MathVision
Claude Opus 4.574.3%
Source
Gemini 3 Flash—
Not directly comparable
CharXiv
Claude Opus 4.568.5%
Source
Gemini 3 Flash—
Not directly comparable
VideoMMMU
Claude Opus 4.584.4%
Source
Gemini 3 Flash—
Not directly comparable
ScreenSpot Pro
Claude Opus 4.545.7%
Source
Gemini 3 Flash—
Not directly comparable
V*
Claude Opus 4.567.0%
Source
Gemini 3 Flash—
Not directly comparable

Knowledge

GPQA
Claude Opus 4.587%
Source
Gemini 3 Flash—
Not directly comparable
SuperGPQA
Claude Opus 4.570.6%
Source
Gemini 3 Flash—
Not directly comparable
MMLU-Pro
Claude Opus 4.589.5%
Source
Gemini 3 Flash—
Not directly comparable
MMLU-Redux
Claude Opus 4.596.6%
Source
Gemini 3 Flash—
Not directly comparable
C-Eval
Claude Opus 4.592.2%
Source
Gemini 3 Flash—
Not directly comparable
HLE
Claude Opus 4.530.8%
Source
Gemini 3 Flash—
Not directly comparable
GPQA Diamond (Vals)
Claude Opus 4.5—
Gemini 3 Flash87.9%
Source
Not directly comparable
MMLU-Pro (Vals)
Claude Opus 4.5—
Gemini 3 Flash88.6%
Source
Not directly comparable

Multilingual

MMLU-ProX
Claude Opus 4.585.7%
Source
Gemini 3 Flash—
Not directly comparable
NOVA-63
Claude Opus 4.556.7%
Source
Gemini 3 Flash—
Not directly comparable

Instruction following

IFEval
Claude Opus 4.590.9%
Source
Gemini 3 Flash—
Not directly comparable
IFBench
Claude Opus 4.558%
Source
Gemini 3 Flash—
Not directly comparable

Math

AIME26
Claude Opus 4.595.1%
Source
Gemini 3 Flash—
Not directly comparable
HMMT Feb 2025
Claude Opus 4.592.9%
Source
Gemini 3 Flash—
Not directly comparable
HMMT Nov 2025
Claude Opus 4.593.3%
Source
Gemini 3 Flash—
Not directly comparable
HMMT Feb 2026
Claude Opus 4.585.3%
Source
Gemini 3 Flash—
Not directly comparable
MMAnswerBench
Claude Opus 4.584.0%
Source
Gemini 3 Flash—
Not directly comparable
FrontierMath v2 (Tiers 1-3)
Shared source
Claude Opus 4.520.690%
Gemini 3 Flash35.640%
Gemini 3 Flash leads this result
FrontierMath v2 (Tier 4)
Shared source
Claude Opus 4.54.167%
Gemini 3 Flash4.167%
Tie

51 public results · 5 shared

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Last updated September 23, 2026

Claude Opus 4.5 vs Gemini 3 Flash

Decision reading

Which one for your work

Long documents

Chat turn cost

Repository review cost

Coding work

Agentic work

Cache-heavy agent loop cost

Which one for a specific job

What is actually comparable

Shape of the matched evidence

Category results, on a stated basis

Agentic

Coding

Knowledge

Instruction following

Reasoning

Multimodal

Multilingual

Math

What each workload costs

Chat turn

Repository review

Cache-heavy agent loop

Specification differences

Context window

API model ID

Cached-input rate

Documented inputs

Documented outputs

Provider availability

Reasoning profile

Weight access

License

Release date

If you already use one of these models

Questions

Which is better, Claude Opus 4.5 or Gemini 3 Flash?

Which is better for coding, Claude Opus 4.5 or Gemini 3 Flash?

Which is better for agentic tasks, Claude Opus 4.5 or Gemini 3 Flash?

Which costs less, Claude Opus 4.5 or Gemini 3 Flash?

Which has the larger context window, Claude Opus 4.5 or Gemini 3 Flash?

Benchmark evidence

Agentic

Coding

Reasoning

Multimodal

Knowledge

Multilingual

Instruction following

Math

Related comparisons

Watch Claude Opus 4.5 vs Gemini 3 Flash