Model Comparison

GPT-5.4 vs Claude Fable 5Which is better in 2026?

Claude Fable 5 significantly outperforms across most benchmarks. GPT-5.4 is 3.6x cheaper per token.

Verdict: GPT-5.4 vs Claude Fable 5 — which is better?

GPT-5.4 (by OpenAI) and Claude Fable 5 (by Anthropic) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

GPT-5.4 outperforms in 0 benchmarks, while Claude Fable 5 is better at 3 benchmarks (Humanity's Last Exam, OSWorld-Verified, SWE-Bench Pro). Claude Fable 5 significantly outperforms across most benchmarks.

On price, GPT-5.4 is roughly 3.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Choose GPT-5.4 if…

  • cost matters — it's about 3.6x cheaper per token

Choose Claude Fable 5 if…

  • you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
  • you want the most recent training data — it shipped Jun 2026
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

GPT-5.4 outperforms in 0 benchmarks, while Claude Fable 5 is better at 3 benchmarks (Humanity's Last Exam, OSWorld-Verified, SWE-Bench Pro).

Claude Fable 5 significantly outperforms across most benchmarks.

Tue Jun 09 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.4 costs less

For input processing, GPT-5.4 ($2.50/1M tokens) is 4.0x cheaper than Claude Fable 5 ($10.00/1M tokens).

For output processing, GPT-5.4 ($15.00/1M tokens) is 3.3x cheaper than Claude Fable 5 ($50.00/1M tokens).

In conclusion, Claude Fable 5 is more expensive than GPT-5.4.*

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

Lowest available price from all providers
Tue Jun 09 2026 • llm-stats.com
OpenAI
GPT-5.4
Input tokens$2.50
Output tokens$15.00
Best providerOpenAI
Anthropic
Claude Fable 5
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
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. Both models can generate responses up to 128,000 tokens.

OpenAI
GPT-5.4
Input1,000,000 tokens
Output128,000 tokens
Anthropic
Claude Fable 5
Input1,000,000 tokens
Output128,000 tokens
Tue Jun 09 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.4 and Claude Fable 5 support multimodal inputs.

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

GPT-5.4

Text
Images
Audio
Video

Claude Fable 5

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.

GPT-5.4

Proprietary

Closed source

Claude Fable 5

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.4 was released on 2026-03-05, while Claude Fable 5 was released on 2026-06-09.

Claude Fable 5 is 3 months newer than GPT-5.4.

GPT-5.4

Mar 5, 2026

3 months ago

Claude Fable 5

Jun 9, 2026

0 days ago

3mo newer

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

GPT-5.4 is available from OpenAI. Claude Fable 5 is available from Anthropic.

GPT-5.4

openai logo
OpenAI
Input Price:Input: $2.50/1MOutput Price:Output: $15.00/1M

Claude Fable 5

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Less expensive input tokens
Less expensive output tokens
Anthropic
Higher Humanity's Last Exam score (64.5% vs 39.8%)
Higher OSWorld-Verified score (85.0% vs 75.0%)
Higher SWE-Bench Pro score (80.0% vs 57.7%)

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5.4
Anthropic
Claude Fable 5

FAQ

Common questions about GPT-5.4 vs Claude Fable 5.

Which is better, GPT-5.4 or Claude Fable 5?

Claude Fable 5 significantly outperforms across most benchmarks. GPT-5.4 is made by OpenAI and Claude Fable 5 is made by Anthropic. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-5.4 compare to Claude Fable 5 in benchmarks?

GPT-5.4 scores Tau2 Telecom: 98.9%, ARC-AGI: 93.7%, Graphwalks BFS <128k: 93.0%, GPQA: 92.8%, Graphwalks parents <128k: 89.8%. Claude Fable 5 scores SWE-Bench Verified: 95.0%, OSWorld-Verified: 85.0%, Terminal-Bench 2.1: 84.3%, SWE-Bench Pro: 80.0%, ExploitBench: 78.0%.

Is GPT-5.4 cheaper than Claude Fable 5?

GPT-5.4 is 4.0x cheaper for input tokens. GPT-5.4 costs $2.50/M input and $15.00/M output via openai. Claude Fable 5 costs $10.00/M input and $50.00/M output via anthropic.

What are the context window sizes for GPT-5.4 and Claude Fable 5?

GPT-5.4 supports 1.0M tokens and Claude Fable 5 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 GPT-5.4 and Claude Fable 5?

Key differences include input pricing ($2.50 vs $10.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.4 and Claude Fable 5?

GPT-5.4 is developed by OpenAI and Claude Fable 5 is developed by Anthropic.

Related comparisons