Model Comparison
GPT-5.5 Instant vs GPT-5.5Which is better in 2026?
GPT-5.5 significantly outperforms across most benchmarks. GPT-5.5 Instant and GPT-5.5 cost the same.
Verdict: GPT-5.5 Instant vs GPT-5.5 — which is better?
GPT-5.5 Instant (by OpenAI) and GPT-5.5 (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.
GPT-5.5 Instant outperforms in 0 benchmarks, while GPT-5.5 is better at 2 benchmarks (GPQA, MMMU-Pro). GPT-5.5 significantly outperforms across most benchmarks.
GPT-5.5 also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.5 Instant if…
- you want the most recent training data — it shipped May 2026
Choose GPT-5.5 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you process long inputs — it offers a 1,050,000 token context window
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.5 Instant outperforms in 0 benchmarks, while GPT-5.5 is better at 2 benchmarks (GPQA, MMMU-Pro).
GPT-5.5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.5 Instant ($5.00/1M tokens) costs the same as GPT-5.5 ($5.00/1M tokens).
For output processing, GPT-5.5 Instant ($30.00/1M tokens) costs the same as GPT-5.5 ($30.00/1M tokens).
In conclusion, GPT-5.5 Instant and GPT-5.5 cost the same.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 accepts 1,050,000 input tokens compared to GPT-5.5 Instant's 400,000 tokens. Both models can generate responses up to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-5.5 Instant and GPT-5.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.5 Instant
GPT-5.5
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-5.5 Instant was released on 2026-05-05, while GPT-5.5 was released on 2026-04-23.
GPT-5.5 Instant is 0 month newer than GPT-5.5.
May 5, 2026
2 months ago
1w newerApr 23, 2026
2 months ago
Knowledge Cutoff
When training data ends
GPT-5.5 Instant has a knowledge cutoff of 2025-08-31, while GPT-5.5 has a cutoff of 2025-12-01.
GPT-5.5 has more recent training data (up to 2025-12-01), making it potentially better informed about events through that date compared to GPT-5.5 Instant (2025-08-31).
Aug 2025
Dec 2025
4 mo newerProvider Availability
GPT-5.5 Instant is available from OpenAI. GPT-5.5 is available from OpenAI.
GPT-5.5 Instant
GPT-5.5
Outputs Comparison
Key Takeaways
No standout differentiators in the data we have for this pair.
GPT-5.5
View detailsOpenAI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.5 Instant and GPT-5.5 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.5 Instant vs GPT-5.5.