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Claude Fable 5.1 vs GLM-5.3-Flash

Claude Fable 5.1 and GLM-5.3-Flash are closely matched at 54.8 and 51.1 on the LLM Stats Score. GLM-5.3-Flash is 84.2x cheaper per token.

Anthropic · Zhipu AI · Updated for 2026

Which is better?

Claude Fable 5.1 and GLM-5.3-Flash are closely matched on the overall LLM Stats Score at 54.8 and 51.1.

In the 3 individual benchmarks reported for both models, Claude Fable 5.1 wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, GLM-5.3-Flash is roughly 84.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GLM-5.3-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

  • you value its reported benchmark strengths — it wins 2 of 3 exact shared results
  • you want the most recent training data — it shipped Sep 2026

Choose GLM-5.3-Flash

  • cost matters — it's about 84.2x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Fable 5.1
Anthropic
GLM-5.3-Flash
Zhipu AI
Core performance indexes
LLM Stats Score
54.8
#5
51.1
#13
Reasoning
52.1
#7
49.8
#15
Agents
39.3
#6
37.7
#11
Cost, coverage & limits
Benchmark wins
2 of 3
1 of 3
Input price
$10.00 / M
$0.15 / M
Output price
$50.00 / M
$0.50 / 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
GLM-5.3-Flash
Vision
40.5#1
31.4#24
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for Claude Fable 5.1 · 15 for GLM-5.3-Flash

3 shared

Claude Fable 5.1 outperforms in 2 benchmarks (GDPval-AA, Humanity's Last Exam), while GLM-5.3-Flash is better at 1 benchmark (AutomationBench).

Claude Fable 5.1 shows notably better performance in the majority of benchmarks.

Tue Sep 01 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GLM-5.3-Flash costs less

For input processing, Claude Fable 5.1 ($10.00/1M tokens) is 66.7x more expensive than GLM-5.3-Flash ($0.15/1M tokens).

For output processing, Claude Fable 5.1 ($50.00/1M tokens) is 100.0x more expensive than GLM-5.3-Flash ($0.50/1M tokens).

In conclusion, Claude Fable 5.1 is more expensive than GLM-5.3-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
Zhipu AI
GLM-5.3-Flash
Input tokens$0.15
Output tokens$0.50
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GLM-5.3-Flash accepts 1,048,576 input tokens compared to Claude Fable 5.1's 1,000,000 tokens. GLM-5.3-Flash can generate longer responses up to 131,072 tokens, while Claude Fable 5.1 is limited to 128,000 tokens.

Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Zhipu AI
GLM-5.3-Flash
Input1,048,576 tokens
Output131,072 tokens
Tue Sep 01 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Fable 5.1 and GLM-5.3-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

GLM-5.3-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Fable 5.1 is licensed under a proprietary license, while GLM-5.3-Flash uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Fable 5.1

Proprietary

Closed source

GLM-5.3-Flash

MIT

Open weights

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while GLM-5.3-Flash was released on 2026-08-26.

Claude Fable 5.1 is 0 month newer than GLM-5.3-Flash.

Claude Fable 5.1

Sep 1, 2026

0 days ago

6d newer
GLM-5.3-Flash

Aug 26, 2026

6 days ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Fable 5.1 is available from Anthropic. GLM-5.3-Flash is available from DeepInfra, FriendliAI, Novita, ZAI.

Claude Fable 5.1

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

GLM-5.3-Flash

deepinfra logo
Deepinfra
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
friendli logo
FriendliAI
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
novita logo
Novita
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
z logo
Unknown Organization
Input Price:Input: $0.15/1MOutput Price:Output: $0.50/1M
* 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 Fable 5.1 and GLM-5.3-Flash side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
GLM-5.3-Flash
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs GLM-5.3-Flash.

Which is better, Claude Fable 5.1 or GLM-5.3-Flash?

Claude Fable 5.1 and GLM-5.3-Flash are closely matched on the LLM Stats Score at 54.8 and 51.1. Claude Fable 5.1 is made by Anthropic and GLM-5.3-Flash is made by Zhipu AI. 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 GLM-5.3-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%. GLM-5.3-Flash scores CharXiv-R: 89.4%, Terminal-Bench 2.1: 84.3%, MMVU: 80.5%, Toolathlon: 78.4%, Chartography: 78.0%.

Is Claude Fable 5.1 cheaper than GLM-5.3-Flash?

GLM-5.3-Flash is 66.7x cheaper for input tokens. Claude Fable 5.1 costs $10.00/M input and $50.00/M output via anthropic. GLM-5.3-Flash costs $0.15/M input and $0.50/M output via deepinfra.

What are the context window sizes for Claude Fable 5.1 and GLM-5.3-Flash?

Claude Fable 5.1 supports 1.0M tokens and GLM-5.3-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 GLM-5.3-Flash?

Key differences include LLM Stats Score (54.8 vs 51.1), context window (1.0M vs 1.0M), input pricing ($10.00 vs $0.15/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and GLM-5.3-Flash?

Claude Fable 5.1 is developed by Anthropic and GLM-5.3-Flash is developed by Zhipu AI.

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