GPT-5.4 vs GPT-5.6 Sol
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.4 is meaningfully stronger at cost efficiency (72 vs 55 on our capability index).
- •GPT-5.6 Sol is meaningfully stronger at reasoning (97 vs 87).
- •GPT-5.4 is 50% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
Specs comparison
| GPT-5.4 | GPT-5.6 Sol | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓1,050,000 tokens (128,000 max output) | Not announced |
| Input / 1M tokens | ✓$2.50 | $5.00 |
| Output / 1M tokens | $15.00 | $30.00 |
| Release date | 2026-03 | 2026-06 |
Benchmarks
| Benchmark | GPT-5.4 | GPT-5.6 Sol |
|---|---|---|
| Terminal-Bench 2.1 | - | 88.8% |
| Terminal-Bench 2.1 (Ultra) | - | 91.9% |
| ExploitBench | - | competitive with Mythos Preview |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose GPT-5.4 if...
- →Large-context tasks where GPT-5.5-level frontier reasoning is not required
- →Cost-conscious production workloads that still need strong capability
- →Migrating from GPT-5.4-based systems where behavior is already tuned
Choose GPT-5.6 Sol if...
- →You are an approved preview partner needing the most capable model for agentic software engineering
- →Complex multi-step tasks that benefit from subagent orchestration (Ultra) or maximum reasoning depth (max)
- →Frontier scientific research, professional knowledge work, or security-sensitive workloads