GPT-5.5 Instant vs Particle-1
GPT-5.5 Instant and Particle-1 are closely matched at 31.7 and 31.9 on the LLM Stats Score. Particle-1 is 25.7x cheaper per token.
OpenAI · Particle AI · Updated for 2026
Which is better?
GPT-5.5 Instant and Particle-1 are closely matched on the overall LLM Stats Score at 31.7 and 31.9.
In the 1 individual benchmarks reported for both models, Particle-1 wins 1; this is a narrower head-to-head signal than the composite indexes.
On price, Particle-1 is roughly 25.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Particle-1 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5.5 Instant
- you want predictable pricing at $5.00/M input and $30.00/M output
Choose Particle-1
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- cost matters — it's about 25.7x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Oct 2026
At a glance
The differences that matter most.
Individual benchmarks
9 reported for GPT-5.5 Instant · 3 for Particle-1
GPT-5.5 Instant outperforms in 0 benchmarks, while Particle-1 is better at 1 benchmark (GPQA).
Particle-1 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.5 Instant ($5.00/1M tokens) is 20.0x more expensive than Particle-1 ($0.25/1M tokens).
For output processing, GPT-5.5 Instant ($30.00/1M tokens) is 30.0x more expensive than Particle-1 ($1.00/1M tokens).
In conclusion, GPT-5.5 Instant is more expensive than Particle-1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Particle-1 accepts 1,048,576 input tokens compared to GPT-5.5 Instant's 400,000 tokens. Particle-1 can generate longer responses up to 131,072 tokens, while GPT-5.5 Instant is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.5 Instant and Particle-1 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.5 Instant
Particle-1
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 Particle-1 was released on 2026-10-28.
Particle-1 is 6 months newer than GPT-5.5 Instant.
May 5, 2026
5 months ago
Oct 28, 2026
-3 days ago
5mo newerKnowledge Cutoff
When training data ends
GPT-5.5 Instant has a documented knowledge cutoff of 2025-08-31, while Particle-1's cutoff date is not specified.
We can confirm GPT-5.5 Instant's training data extends to 2025-08-31, but cannot make a direct comparison without Particle-1's cutoff date.
Aug 2025
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Provider Availability
GPT-5.5 Instant is available from OpenAI. Particle-1 is available from Particle AI.
GPT-5.5 Instant
Particle-1
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.5 Instant and Particle-1 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.5 Instant vs Particle-1.