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Claude Opus 4.8 vs Gemini 3.5 Flash

Claude Opus 4.8 leads the LLM Stats Score 50.8 to 42.6. Gemini 3.5 Flash is 3.0x cheaper per token.

Anthropic · Google · Updated for 2026

Which is better?

Claude Opus 4.8 leads the overall LLM Stats Score 50.8 to 42.6, ranking #15 overall.

In the 11 individual benchmarks reported for both models, Claude Opus 4.8 wins 7; this is a narrower head-to-head signal than the composite indexes.

On price, Gemini 3.5 Flash is roughly 3.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 4.8

  • overall performance matters — it scores 50.8 and ranks #15 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 7 of 11 exact shared results
  • you want the most recent training data — it shipped May 2026

Choose Gemini 3.5 Flash

  • cost matters — it's about 3.0x cheaper per token

At a glance

The differences that matter most.

Core performance indexes
50.8
#15
42.6
#47
50.3
#13
43.4
#40
41.6
#11
31.3
#43
35.3
#19
29.5
#36
Cost, coverage & limits
Benchmark wins
7 of 11
4 of 11
Input price
$5.00 / M
$1.50 / M
Output price
$25.00 / M
$9.00 / M
Context window
1,000,000
1,000,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

6 shared
Index
Claude Opus 4.8
Gemini 3.5 Flash
39.3#20
30.6#73
36.4#7
31.7#25
30.4#17
30.6#16
20.7#28
7.8#92
36.1#8
33.2#19
1 more shared indexes
26.7#40
30.4#24
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

27 reported for Claude Opus 4.8 · 16 for Gemini 3.5 Flash

11 shared

Claude Opus 4.8 outperforms in 7 benchmarks (CharXiv-R, DeepSWE 1.1, Humanity's Last Exam, LiveBench, OSWorld-Verified, SWE-Bench Pro, Toolathlon), while Gemini 3.5 Flash is better at 4 benchmarks (Finance Agent, Finance Agent v2, MCP Atlas, Terminal-Bench 2.0).

Claude Opus 4.8 shows notably better performance in the majority of benchmarks.

Sun Sep 20 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Gemini 3.5 Flash costs less

For input processing, Claude Opus 4.8 ($5.00/1M tokens) is 3.3x more expensive than Gemini 3.5 Flash ($1.50/1M tokens).

For output processing, Claude Opus 4.8 ($25.00/1M tokens) is 2.8x more expensive than Gemini 3.5 Flash ($9.00/1M tokens).

In conclusion, Claude Opus 4.8 is more expensive than Gemini 3.5 Flash.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sun Sep 20 2026 • llm-stats.com
Anthropic
Claude Opus 4.8
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
Google
Gemini 3.5 Flash
Input tokens$1.50
Output tokens$9.00
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Both models have the same input context window of 1,000,000 tokens. Gemini 3.5 Flash can generate longer responses up to 1,000,000 tokens, while Claude Opus 4.8 is limited to 128,000 tokens.

Anthropic
Claude Opus 4.8
Input1,000,000 tokens
Output128,000 tokens
Google
Gemini 3.5 Flash
Input1,000,000 tokens
Output1,000,000 tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 4.8 and Gemini 3.5 Flash support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 4.8

Text
Images
Audio
Video

Gemini 3.5 Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 4.8

Proprietary

Closed source

Gemini 3.5 Flash

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.8 was released on 2026-05-28, while Gemini 3.5 Flash was released on 2026-05-19.

Claude Opus 4.8 is 0 month newer than Gemini 3.5 Flash.

Claude Opus 4.8

May 28, 2026

3 months ago

1w newer
Gemini 3.5 Flash

May 19, 2026

4 months ago

Knowledge Cutoff

When training data ends

Gemini 3.5 Flash has a documented knowledge cutoff of 2026-01-31, while Claude Opus 4.8's cutoff date is not specified.

We can confirm Gemini 3.5 Flash's training data extends to 2026-01-31, but cannot make a direct comparison without Claude Opus 4.8's cutoff date.

Claude Opus 4.8

Gemini 3.5 Flash

Jan 2026

Provider Availability

Claude Opus 4.8 is available from Anthropic, DeepInfra, Vertex AI. Gemini 3.5 Flash is available from DeepInfra, Google.

Claude Opus 4.8

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
deepinfra logo
Deepinfra
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
vertex logo
Unknown Organization
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

Gemini 3.5 Flash

deepinfra logo
Deepinfra
Input Price:Input: $1.50/1MOutput Price:Output: $9.00/1M
google logo
Google
Input Price:Input: $1.50/1MOutput Price:Output: $9.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Claude Opus 4.8 and Gemini 3.5 Flash side-by-side, then vote on the output you prefer.

Claude Opus 4.8
✓ Preferred
Gemini 3.5 Flash
Open in Playground

FAQ

Common questions about Claude Opus 4.8 vs Gemini 3.5 Flash.

Which is better, Claude Opus 4.8 or Gemini 3.5 Flash?

Claude Opus 4.8 leads the LLM Stats Score 50.8 to 42.6. Claude Opus 4.8 is made by Anthropic and Gemini 3.5 Flash is made by Google. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 4.8 compare to Gemini 3.5 Flash in benchmarks?

Claude Opus 4.8 scores GPQA: 93.6%, DeepSearchQA: 93.1%, CharXiv-R: 89.9%, SWE-Bench Verified: 88.6%, ScreenSpot Pro: 87.9%. Gemini 3.5 Flash scores CharXiv-R: 84.2%, MCP Atlas: 83.6%, MMMU-Pro: 83.6%, OSWorld-Verified: 78.4%, Terminal-Bench 2.0: 76.2%.

Is Claude Opus 4.8 cheaper than Gemini 3.5 Flash?

Gemini 3.5 Flash is 3.3x cheaper for input tokens. Claude Opus 4.8 costs $5.00/M input and $25.00/M output via anthropic. Gemini 3.5 Flash costs $1.50/M input and $9.00/M output via deepinfra.

What are the context window sizes for Claude Opus 4.8 and Gemini 3.5 Flash?

Claude Opus 4.8 supports 1.0M tokens and Gemini 3.5 Flash supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.8 and Gemini 3.5 Flash?

Key differences include LLM Stats Score (50.8 vs 42.6), input pricing ($5.00 vs $1.50/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.8 and Gemini 3.5 Flash?

Claude Opus 4.8 is developed by Anthropic and Gemini 3.5 Flash is developed by Google.