GPT-5.5 Pro vs GPT-5.6 Sol: Specs & Benchmark Comparison
GPT-5.5 Pro and GPT-5.6 Sol both come from OpenAI, GPT-5.5 Pro was released in April 2026, and GPT-5.6 Sol followed 3 months later in July 2026.
The two models share 2 published benchmarks. GPT-5.6 Sol leads on 2 of them. The widest gaps are on FrontierMath, where GPT-5.6 Sol scores 89.0% against 39.6%; BrowseComp, where GPT-5.6 Sol scores 90.4% against 90.1%. Averaged across everything we track, GPT-5.5 Pro sits at 60.5% and GPT-5.6 Sol at 63.9%.
GPT-5.6 Sol is the cheaper API at $5 per million input tokens and $30 per million output tokens, roughly 6 times cheaper than GPT-5.5 Pro at $30 and $180. Both accept a context window of about 1M tokens. Both accept text and images as input. On tooling, only GPT-5.6 Sol supports function calling and only GPT-5.6 Sol offers structured output.
| Characteristic | GPT-5.5 Pro | GPT-5.6 Sol |
|---|---|---|
| Company | OpenAI | OpenAI |
| Release Date | April 23, 2026 | July 9, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.1M | 1.1M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $30.00 | $5.00 |
| Output Price / 1M | $180.00 | $30.00 |
| Average Score | 60.5% | 63.9% |
| Benchmarks | ||
| FrontierMath | 39.6% | 89.0% |
| BrowseComp | 90.1% | 90.4% |
Visual Benchmark Comparison
Verdict
GPT-5.6 Sol leads in 2 out of 4 comparison categories.
Both models show comparable average scores: GPT-5.5 Pro — 0.6, GPT-5.6 Sol — 0.6.
GPT-5.6 Sol is 6.0x cheaper: input $5.00/1M vs $30.00/1M tokens.
Same context size: 1M tokens.
GPT-5.6 Sol is newer: released 7/9/2026 vs 4/23/2026.
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Frequently Asked Questions
Which is better for coding — GPT-5.5 Pro or GPT-5.6 Sol?
Which model is cheaper — GPT-5.5 Pro or GPT-5.6 Sol?
Which has a larger context window — GPT-5.5 Pro or GPT-5.6 Sol?
The GPT-5.5 Pro and GPT-5.6 Sol comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.5 Pro or GPT-5.6 Sol page. See also the complete list of AI model comparisons.