Model Comparison

GPT-5.5 Instant vs GPT-5.5 ProWhich is better in 2026?

Comparing GPT-5.5 Instant and GPT-5.5 Pro across benchmarks, pricing, and capabilities.

Verdict: GPT-5.5 Instant vs GPT-5.5 Pro — which is better?

GPT-5.5 Instant (by OpenAI) and GPT-5.5 Pro (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.

On price, GPT-5.5 Instant is roughly 6.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.5 Pro 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…

  • cost matters — it's about 6.0x cheaper per token
  • you want the most recent training data — it shipped May 2026

Choose GPT-5.5 Pro if…

  • you process long inputs — it offers a 1,050,000 token context window

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.5 Instant and GPT-5.5 Prodon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.5 Instant costs less

For input processing, GPT-5.5 Instant ($5.00/1M tokens) is 6.0x cheaper than GPT-5.5 Pro ($30.00/1M tokens).

For output processing, GPT-5.5 Instant ($30.00/1M tokens) is 6.0x cheaper than GPT-5.5 Pro ($180.00/1M tokens).

In conclusion, GPT-5.5 Pro is more expensive than GPT-5.5 Instant.*

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

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
OpenAI
GPT-5.5 Instant
Input tokens$5.00
Output tokens$30.00
Best providerOpenAI
OpenAI
GPT-5.5 Pro
Input tokens$30.00
Output tokens$180.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 Pro 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.

OpenAI
GPT-5.5 Instant
Input400,000 tokens
Output128,000 tokens
OpenAI
GPT-5.5 Pro
Input1,050,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.5 Instant and GPT-5.5 Pro support multimodal inputs.

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

GPT-5.5 Instant

Text
Images
Audio
Video

GPT-5.5 Pro

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-5.5 Instant

Proprietary

Closed source

GPT-5.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.5 Instant was released on 2026-05-05, while GPT-5.5 Pro was released on 2026-04-23.

GPT-5.5 Instant is 0 month newer than GPT-5.5 Pro.

GPT-5.5 Instant

May 5, 2026

2 months ago

1w newer
GPT-5.5 Pro

Apr 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 Pro has a cutoff of 2025-12-01.

GPT-5.5 Pro 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).

GPT-5.5 Instant

Aug 2025

GPT-5.5 Pro

Dec 2025

4 mo newer

Provider Availability

GPT-5.5 Instant is available from OpenAI. GPT-5.5 Pro is available from OpenAI.

GPT-5.5 Instant

openai logo
OpenAI
Input Price:Input: $5.00/1MOutput Price:Output: $30.00/1M

GPT-5.5 Pro

openai logo
OpenAI
Input Price:Input: $30.00/1MOutput Price:Output: $180.00/1M
* 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
OpenAI
Larger context window (1,050,000 tokens)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.5 Instant and GPT-5.5 Pro side-by-side, then vote on the output you prefer.

GPT-5.5 Instant
✓ Preferred
GPT-5.5 Pro
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.5 Instant
OpenAI
GPT-5.5 Pro

FAQ

Common questions about GPT-5.5 Instant vs GPT-5.5 Pro.

Which is better, GPT-5.5 Instant or GPT-5.5 Pro?

GPT-5.5 Instant (OpenAI) and GPT-5.5 Pro (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5.5 Instant compare to GPT-5.5 Pro in benchmarks?

GPT-5.5 Instant scores HealthBench Consensus: 94.7%, OmniDocBench 1.5: 87.5%, GPQA: 85.6%, CharXiv-R: 81.6%, AIME 2025: 81.2%. GPT-5.5 Pro scores BrowseComp: 90.1%, GDPval-MM: 82.3%, Humanity's Last Exam: 57.2%, FrontierMath: 39.6%, GeneBench: 33.2%.

Is GPT-5.5 Instant cheaper than GPT-5.5 Pro?

GPT-5.5 Instant is 6.0x cheaper for input tokens. GPT-5.5 Instant costs $5.00/M input and $30.00/M output via openai. GPT-5.5 Pro costs $30.00/M input and $180.00/M output via openai.

What are the context window sizes for GPT-5.5 Instant and GPT-5.5 Pro?

GPT-5.5 Instant supports 400K tokens and GPT-5.5 Pro supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.5 Instant and GPT-5.5 Pro?

Key differences include context window (400K vs 1.1M), input pricing ($5.00 vs $30.00/M). See the full comparison above for benchmark-by-benchmark results.

Related comparisons