GPT-5.5 vs Particle-1
GPT-5.5 leads the LLM Stats Score 47.0 to 32.0. Particle-1 is 25.7x cheaper per token.
OpenAI · Particle AI · Updated for 2026
Which is better?
GPT-5.5 leads the overall LLM Stats Score 47.0 to 32.0, ranking #40 overall.
In the 1 individual benchmarks reported for both models, GPT-5.5 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.
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.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5.5
- overall performance matters — it scores 47.0 and ranks #40 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- you process long inputs — it offers a 1,050,000 token context window
Choose Particle-1
- cost matters — it's about 25.7x cheaper per token
- you want the most recent training data — it shipped Oct 2026
At a glance
The differences that matter most.
Individual benchmarks
28 reported for GPT-5.5 · 3 for Particle-1
GPT-5.5 outperforms in 1 benchmarks (GPQA), while Particle-1 is better at 0 benchmarks.
GPT-5.5 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 ($5.00/1M tokens) is 20.0x more expensive than Particle-1 ($0.25/1M tokens).
For output processing, GPT-5.5 ($30.00/1M tokens) is 30.0x more expensive than Particle-1 ($1.00/1M tokens).
In conclusion, GPT-5.5 is more expensive than Particle-1.*
* 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 Particle-1's 1,048,576 tokens. Particle-1 can generate longer responses up to 131,072 tokens, while GPT-5.5 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.5 and Particle-1 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.5
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 was released on 2026-04-23, while Particle-1 was released on 2026-10-28.
Particle-1 is 6 months newer than GPT-5.5.
Apr 23, 2026
6 months ago
Oct 28, 2026
1 weeks ago
6mo newerKnowledge Cutoff
When training data ends
GPT-5.5 has a documented knowledge cutoff of 2025-12-01, while Particle-1's cutoff date is not specified.
We can confirm GPT-5.5's training data extends to 2025-12-01, but cannot make a direct comparison without Particle-1's cutoff date.
Dec 2025
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Provider Availability
GPT-5.5 is available from OpenAI. Particle-1 is available from Particle AI.
GPT-5.5
Particle-1
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.5 and Particle-1 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.5 vs Particle-1.