Model Comparison
GPT-5.4 vs Claude Sonnet 4.5Which is better in 2026?
GPT-5.4 significantly outperforms across most benchmarks. GPT-5.4 is 1.1x cheaper per token.
Verdict: GPT-5.4 vs Claude Sonnet 4.5 — which is better?
GPT-5.4 (by OpenAI) and Claude Sonnet 4.5 (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 1 benchmarks (GPQA), while Claude Sonnet 4.5 is better at 0 benchmarks. GPT-5.4 significantly outperforms across most benchmarks.
On price, GPT-5.4 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.4 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.4 if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- cost matters — it's about 1.1x cheaper per token
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Mar 2026
Choose Claude Sonnet 4.5 if…
- you want predictable pricing at $3.00/M input and $15.00/M output
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.4 outperforms in 1 benchmarks (GPQA), while Claude Sonnet 4.5 is better at 0 benchmarks.
GPT-5.4 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.4 ($2.50/1M tokens) is 1.2x cheaper than Claude Sonnet 4.5 ($3.00/1M tokens).
For output processing, GPT-5.4 ($15.00/1M tokens) costs the same as Claude Sonnet 4.5 ($15.00/1M tokens).
In conclusion, Claude Sonnet 4.5 is more expensive than GPT-5.4.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.4 accepts 1,000,000 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. GPT-5.4 can generate longer responses up to 128,000 tokens, while Claude Sonnet 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-5.4 and Claude Sonnet 4.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.4
Claude Sonnet 4.5
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5.4 was released on 2026-03-05, while Claude Sonnet 4.5 was released on 2025-09-29.
GPT-5.4 is 5 months newer than Claude Sonnet 4.5.
Mar 5, 2026
3 months ago
5mo newerSep 29, 2025
8 months ago
Knowledge Cutoff
When training data ends
Claude Sonnet 4.5 has a documented knowledge cutoff of 2025-01-31, while GPT-5.4's cutoff date is not specified.
We can confirm Claude Sonnet 4.5's training data extends to 2025-01-31, but cannot make a direct comparison without GPT-5.4's cutoff date.
—
Jan 2025
Provider Availability
GPT-5.4 is available from OpenAI. Claude Sonnet 4.5 is available from Anthropic.
GPT-5.4
Claude Sonnet 4.5
Outputs Comparison
Key Takeaways
GPT-5.4
View detailsOpenAI
Claude Sonnet 4.5
View detailsAnthropic
No standout differentiators in the data we have for this pair.
Detailed Comparison
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FAQ
Common questions about GPT-5.4 vs Claude Sonnet 4.5.