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Claude Opus 5.5 vs Gemini 3.5 Flash-Lite

Claude Opus 5.5 leads the LLM Stats Score 59.8 to 29.7. Gemini 3.5 Flash-Lite is 9.4x cheaper per token.

Anthropic · Google · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 59.8 to 29.7, ranking #1 overall.

In the 1 individual benchmarks reported for both models, Claude Opus 5.5 wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, Gemini 3.5 Flash-Lite is roughly 9.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3.5 Flash-Lite also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose Claude Opus 5.5

  • overall performance matters — it scores 59.8 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Sep 2026

Choose Gemini 3.5 Flash-Lite

  • cost matters — it's about 9.4x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Gemini 3.5 Flash-Lite
Google
Core performance indexes
LLM Stats Score
59.8
#1
29.7
#128
Reasoning
57.9
#1
25.7
#153
Coding
51.8
#1
15.6
#133
Agents
44.6
#2
15.2
#90
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$4.00 / M
$0.30 / M
Output price
$20.00 / M
$2.50 / M
Context window
1,000,000
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Claude Opus 5.5
Gemini 3.5 Flash-Lite
Vision
42.9#1
19.3#77
Multimodal
42.6#1
21.6#66
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 6 for Gemini 3.5 Flash-Lite

1 shared

Claude Opus 5.5 outperforms in 1 benchmarks (SWE-Bench Pro), while Gemini 3.5 Flash-Lite is better at 0 benchmarks.

Claude Opus 5.5 significantly outperforms across most benchmarks.

Tue Sep 22 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-Lite costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 13.3x more expensive than Gemini 3.5 Flash-Lite ($0.30/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 8.0x more expensive than Gemini 3.5 Flash-Lite ($2.50/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than Gemini 3.5 Flash-Lite.*

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

Lowest available price from all providers
Tue Sep 22 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
Google
Gemini 3.5 Flash-Lite
Input tokens$0.30
Output tokens$2.50
Best providerGoogle
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3.5 Flash-Lite accepts 1,048,576 input tokens compared to Claude Opus 5.5's 1,000,000 tokens. Claude Opus 5.5 can generate longer responses up to 128,000 tokens, while Gemini 3.5 Flash-Lite is limited to 65,536 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Google
Gemini 3.5 Flash-Lite
Input1,048,576 tokens
Output65,536 tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and Gemini 3.5 Flash-Lite support multimodal inputs.

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

Claude Opus 5.5

Text
Images
Audio
Video

Gemini 3.5 Flash-Lite

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 5.5

Proprietary

Closed source

Gemini 3.5 Flash-Lite

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Gemini 3.5 Flash-Lite was released on 2026-07-21.

Claude Opus 5.5 is 2 months newer than Gemini 3.5 Flash-Lite.

Claude Opus 5.5

Sep 22, 2026

0 days ago

2mo newer
Gemini 3.5 Flash-Lite

Jul 21, 2026

2 months ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a knowledge cutoff of 2026-06-01, while Gemini 3.5 Flash-Lite has a cutoff of 2026-03-31.

Claude Opus 5.5 has more recent training data (up to 2026-06-01), making it potentially better informed about events through that date compared to Gemini 3.5 Flash-Lite (2026-03-31).

Claude Opus 5.5

Jun 2026

3 mo newer
Gemini 3.5 Flash-Lite

Mar 2026

Provider Availability

Claude Opus 5.5 is available from Anthropic. Gemini 3.5 Flash-Lite is available from Google.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

Gemini 3.5 Flash-Lite

google logo
Google
Input Price:Input: $0.30/1MOutput Price:Output: $2.50/1M
* 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 5.5 and Gemini 3.5 Flash-Lite side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Gemini 3.5 Flash-Lite
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Gemini 3.5 Flash-Lite.

Which is better, Claude Opus 5.5 or Gemini 3.5 Flash-Lite?

Claude Opus 5.5 leads the LLM Stats Score 59.8 to 29.7. Claude Opus 5.5 is made by Anthropic and Gemini 3.5 Flash-Lite 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 5.5 compare to Gemini 3.5 Flash-Lite in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. Gemini 3.5 Flash-Lite scores CharXiv-R: 76.5%, OSWorld-Verified: 74.0%, SWE-Bench Pro: 54.2%, Terminal-Bench 2.1: 54.0%, MLE-Bench: 39.2%.

Is Claude Opus 5.5 cheaper than Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite is 13.3x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Gemini 3.5 Flash-Lite costs $0.30/M input and $2.50/M output via google.

What are the context window sizes for Claude Opus 5.5 and Gemini 3.5 Flash-Lite?

Claude Opus 5.5 supports 1.0M tokens and Gemini 3.5 Flash-Lite 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 5.5 and Gemini 3.5 Flash-Lite?

Key differences include LLM Stats Score (59.8 vs 29.7), context window (1.0M vs 1.0M), input pricing ($4.00 vs $0.30/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Gemini 3.5 Flash-Lite?

Claude Opus 5.5 is developed by Anthropic and Gemini 3.5 Flash-Lite is developed by Google.

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