GPT-5.5 Instant vs GPT-6.1 Sol
GPT-6.1 Sol leads the LLM Stats Score 52.0 to 32.2. GPT-6.1 Sol is 2.8x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
GPT-6.1 Sol leads the overall LLM Stats Score 52.0 to 32.2, ranking #11 overall.
In the 4 individual benchmarks reported for both models, GPT-6.1 Sol wins 4; this is a narrower head-to-head signal than the composite indexes.
On price, GPT-6.1 Sol is roughly 2.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-6.1 Sol 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 Instant
- you want predictable pricing at $5.00/M input and $30.00/M output
Choose GPT-6.1 Sol
- overall performance matters — it scores 52.0 and ranks #11 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 4 of 4 exact shared results
- cost matters — it's about 2.8x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Sep 2026
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
9 reported for GPT-5.5 Instant · 10 for GPT-6.1 Sol
GPT-5.5 Instant outperforms in 0 benchmarks, while GPT-6.1 Sol is better at 4 benchmarks (HealthBench, HealthBench Consensus, HealthBench Hard, HealthBench Professional).
GPT-6.1 Sol 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 2.5x more expensive than GPT-6.1 Sol ($2.00/1M tokens).
For output processing, GPT-5.5 Instant ($30.00/1M tokens) is 3.0x more expensive than GPT-6.1 Sol ($10.00/1M tokens).
In conclusion, GPT-5.5 Instant is more expensive than GPT-6.1 Sol.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-6.1 Sol 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
Documented input modalities across available providers
Both GPT-5.5 Instant and GPT-6.1 Sol support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.5 Instant
GPT-6.1 Sol
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-6.1 Sol was released on 2026-09-29.
GPT-6.1 Sol is 5 months newer than GPT-5.5 Instant.
May 5, 2026
5 months ago
Sep 29, 2026
5 days ago
4mo newerKnowledge Cutoff
When training data ends
GPT-5.5 Instant has a knowledge cutoff of 2025-08-31, while GPT-6.1 Sol has a cutoff of 2026-04-30.
GPT-6.1 Sol has more recent training data (up to 2026-04-30), making it potentially better informed about events through that date compared to GPT-5.5 Instant (2025-08-31).
Aug 2025
Apr 2026
8 mo newerProvider Availability
GPT-5.5 Instant is available from OpenAI. GPT-6.1 Sol is available from OpenAI.
GPT-5.5 Instant
GPT-6.1 Sol
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.5 Instant and GPT-6.1 Sol side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.5 Instant vs GPT-6.1 Sol.