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Claude Fable 5.1 vs Gemini 1.5 Flash

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 6.2. Gemini 1.5 Flash is 76.2x cheaper per token.

Anthropic · Google · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 54.8 to 6.2, ranking #5 overall.

On price, Gemini 1.5 Flash is roughly 76.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 1.5 Flash 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 Fable 5.1

  • overall performance matters — it scores 54.8 and ranks #5 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Gemini 1.5 Flash

  • cost matters — it's about 76.2x 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 Fable 5.1
Anthropic
Gemini 1.5 Flash
Google
Core performance indexes
LLM Stats Score
54.8
#5
6.2
#278
Reasoning
52.1
#7
5.8
#277
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
$0.15 / M
Output price
$50.00 / M
$0.60 / M
Context window
1,000,000
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Fable 5.1
Gemini 1.5 Flash
Vision
40.5#1
5.9#144
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for Claude Fable 5.1 · 22 for Gemini 1.5 Flash

No common benchmarks found

Claude Fable 5.1 and Gemini 1.5 Flashdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Gemini 1.5 Flash costs less

For input processing, Claude Fable 5.1 ($10.00/1M tokens) is 66.7x more expensive than Gemini 1.5 Flash ($0.15/1M tokens).

For output processing, Claude Fable 5.1 ($50.00/1M tokens) is 83.3x more expensive than Gemini 1.5 Flash ($0.60/1M tokens).

In conclusion, Claude Fable 5.1 is more expensive than Gemini 1.5 Flash.*

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

Lowest available price from all providers
Tue Sep 01 2026 • llm-stats.com
Anthropic
Claude Fable 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Google
Gemini 1.5 Flash
Input tokens$0.15
Output tokens$0.60
Best providerGoogle
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 1.5 Flash accepts 1,048,576 input tokens compared to Claude Fable 5.1's 1,000,000 tokens. Claude Fable 5.1 can generate longer responses up to 128,000 tokens, while Gemini 1.5 Flash is limited to 8,192 tokens.

Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Google
Gemini 1.5 Flash
Input1,048,576 tokens
Output8,192 tokens
Tue Sep 01 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Fable 5.1 and Gemini 1.5 Flash support multimodal inputs.

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

Claude Fable 5.1

Text
Images
Audio
Video

Gemini 1.5 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 Fable 5.1

Proprietary

Closed source

Gemini 1.5 Flash

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while Gemini 1.5 Flash was released on 2024-05-01.

Claude Fable 5.1 is 28 months newer than Gemini 1.5 Flash.

Claude Fable 5.1

Sep 1, 2026

0 days ago

2.3yr newer
Gemini 1.5 Flash

May 1, 2024

2.3 years ago

Knowledge Cutoff

When training data ends

Gemini 1.5 Flash has a documented knowledge cutoff of 2023-11-01, while Claude Fable 5.1's cutoff date is not specified.

We can confirm Gemini 1.5 Flash's training data extends to 2023-11-01, but cannot make a direct comparison without Claude Fable 5.1's cutoff date.

Claude Fable 5.1

—

Gemini 1.5 Flash

Nov 2023

Provider Availability

Claude Fable 5.1 is available from Anthropic. Gemini 1.5 Flash is available from Google.

Claude Fable 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

Gemini 1.5 Flash

google logo
Google
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
* 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 Fable 5.1 and Gemini 1.5 Flash side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
Gemini 1.5 Flash
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs Gemini 1.5 Flash.

Which is better, Claude Fable 5.1 or Gemini 1.5 Flash?

Claude Fable 5.1 leads the LLM Stats Score 54.8 to 6.2. Claude Fable 5.1 is made by Anthropic and Gemini 1.5 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 Fable 5.1 compare to Gemini 1.5 Flash in benchmarks?

Claude Fable 5.1 scores OSWorld 2.0: 77.9%, CursorBench v3.2: 73.4%, Humanity's Last Exam: 65.0%, GDPval-AA: 61.8%, Terminal-Bench 4.0: 55.8%. Gemini 1.5 Flash scores XSTest: 97.0%, FLEURS: 90.4%, HellaSwag: 86.5%, GSM8k: 86.2%, BIG-Bench Hard: 85.5%.

Is Claude Fable 5.1 cheaper than Gemini 1.5 Flash?

Gemini 1.5 Flash is 66.7x cheaper for input tokens. Claude Fable 5.1 costs $10.00/M input and $50.00/M output via anthropic. Gemini 1.5 Flash costs $0.15/M input and $0.60/M output via google.

What are the context window sizes for Claude Fable 5.1 and Gemini 1.5 Flash?

Claude Fable 5.1 supports 1.0M tokens and Gemini 1.5 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 Fable 5.1 and Gemini 1.5 Flash?

Key differences include LLM Stats Score (54.8 vs 6.2), context window (1.0M vs 1.0M), input pricing ($10.00 vs $0.15/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and Gemini 1.5 Flash?

Claude Fable 5.1 is developed by Anthropic and Gemini 1.5 Flash is developed by Google.

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