Model Comparison
Claude Haiku 4.5 vs GPT-5.5 InstantWhich is better in 2026?
GPT-5.5 Instant significantly outperforms across most benchmarks. Claude Haiku 4.5 is 5.6x cheaper per token.
Verdict: Claude Haiku 4.5 vs GPT-5.5 Instant — which is better?
Claude Haiku 4.5 (by Anthropic) and GPT-5.5 Instant (by OpenAI) 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.
Claude Haiku 4.5 outperforms in 0 benchmarks, while GPT-5.5 Instant is better at 2 benchmarks (AIME 2025, GPQA). GPT-5.5 Instant significantly outperforms across most benchmarks.
On price, Claude Haiku 4.5 is roughly 5.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.5 Instant also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose Claude Haiku 4.5 if…
- cost matters — it's about 5.6x cheaper per token
Choose GPT-5.5 Instant if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped May 2026
Performance Benchmarks
Comparative analysis across standard metrics
Claude Haiku 4.5 outperforms in 0 benchmarks, while GPT-5.5 Instant is better at 2 benchmarks (AIME 2025, GPQA).
GPT-5.5 Instant significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Haiku 4.5 ($1.00/1M tokens) is 5.0x cheaper than GPT-5.5 Instant ($5.00/1M tokens).
For output processing, Claude Haiku 4.5 ($5.00/1M tokens) is 6.0x cheaper than GPT-5.5 Instant ($30.00/1M tokens).
In conclusion, GPT-5.5 Instant is more expensive than Claude Haiku 4.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 Instant accepts 400,000 input tokens compared to Claude Haiku 4.5's 200,000 tokens. GPT-5.5 Instant can generate longer responses up to 128,000 tokens, while Claude Haiku 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Haiku 4.5 and GPT-5.5 Instant support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Haiku 4.5
GPT-5.5 Instant
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
Claude Haiku 4.5 was released on 2025-10-15, while GPT-5.5 Instant was released on 2026-05-05.
GPT-5.5 Instant is 7 months newer than Claude Haiku 4.5.
Oct 15, 2025
9 months ago
May 5, 2026
2 months ago
6mo newerKnowledge Cutoff
When training data ends
Claude Haiku 4.5 has a knowledge cutoff of 2025-02-01, while GPT-5.5 Instant has a cutoff of 2025-08-31.
GPT-5.5 Instant has more recent training data (up to 2025-08-31), making it potentially better informed about events through that date compared to Claude Haiku 4.5 (2025-02-01).
Feb 2025
Aug 2025
6 mo newerProvider Availability
Claude Haiku 4.5 is available from Anthropic, Vertex AI. GPT-5.5 Instant is available from OpenAI.
Claude Haiku 4.5
GPT-5.5 Instant
Outputs Comparison
Key Takeaways
Claude Haiku 4.5
View detailsAnthropic
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Claude Haiku 4.5 and GPT-5.5 Instant side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Claude Haiku 4.5 vs GPT-5.5 Instant.