GPT-5.4 Pro vs GPT-5.6 Sol Pro
GPT-5.6 Sol Pro costs 9.0x less per output token than GPT-5.4 Pro ($20.00 vs $180.00 per million). Updated October 22, 2026; 4 benchmarks have a result for both.
GPT-5.4 Pro or GPT-5.6 Sol Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GPT-5.4 Pro for work measured by WeirdML or Chess puzzles, where it leads.
- Shared results
- 4
- GPT-5.4 Pro only
- 6
- GPT-5.6 Sol Pro only
- 3
- Like-for-like categories
- 3 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
No call
Both take 1.05M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Sol Pro
GPT-5.4 Pro $0.120, GPT-5.6 Sol Pro $0.014 per turn.
List prices
At a glance
- Coding index
- GPT-5.4 Pro not benchmarked, GPT-5.6 Sol Pro not benchmarked.
- Widest category
- Coding, 32.0 points apart on average over 1 shared benchmark.
- Widest single gap
- WeirdML: GPT-5.4 Pro 57.4% against GPT-5.6 Sol Pro 89.4%, 32.0 points apart on a 0 to 100 scale.
- Output price
- GPT-5.4 Pro $180.00 against GPT-5.6 Sol Pro $20.00 per million output tokens, 9.0x apart.
- Context window
- Both take 1.05M tokens.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | GPT-5.4 Pro | Bars | GPT-5.6 Sol Pro | Ties |
|---|---|---|---|---|
| Coding | 0 | 1 | ||
| Reasoning | 1 | 1 | ||
| Math | 0 | 1 | ||
| All shared boards | 1 | 3 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index01
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| WeirdML | 57.4% | 89.4% | GPT-5.6 Sol Pro |
| Neither model has a result on the other 38 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 159.6 | Not measured | Only GPT-5.4 Pro measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| APEX-Agents | Not measured | 51.4% | Only GPT-5.6 Sol Pro measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| GPQA Diamond (Epoch AI run) | 94.6% | Not measured | Only GPT-5.4 Pro measured |
| ARC-AGI | 94.5% | Not measured | Only GPT-5.4 Pro measured |
| ARC-AGI-2 | 83.3% | Not measured | Only GPT-5.4 Pro measured |
| SimpleBench | 74.1% | 71.7% | GPT-5.4 Pro |
| Chess puzzles | 59.0% | 68.0% | GPT-5.6 Sol Pro |
| Neither model has a result on the other 17 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| FrontierMath, tiers 1 to 3 | 82.5% | Not measured | Only GPT-5.4 Pro measured |
| FrontierMath, tier 4 | 58.5% | 80.5% | GPT-5.6 Sol Pro |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| SimpleQA Verified | 46.3% | Not measured | Only GPT-5.4 Pro measured |
| Neither model has a result on the other 17 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Neither model has a result on 9 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.4 Pro | GPT-5.6 Sol Pro | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
GPT-5.6 Sol Pro costs less
Repository review
50K input + 3K output tokens
GPT-5.6 Sol Pro costs less
Agent loop
200K input + 10K output tokens
GPT-5.6 Sol Pro costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | OpenAI GPT-5.4 Pro | OpenAI GPT-5.6 Sol Pro |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | March 5, 2026 | July 9, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $30.00 | $4.00 |
| Output $/Mtok | $180.00 | $20.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.4 Pro better than GPT-5.6 Sol Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GPT-5.4 Pro for work measured by WeirdML or Chess puzzles, where it leads.
Which is cheaper, GPT-5.4 Pro or GPT-5.6 Sol Pro?
GPT-5.4 Pro costs $30.00 per million input tokens and $180.00 per million output tokens; GPT-5.6 Sol Pro costs $4.00 and $20.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5.4 Pro or GPT-5.6 Sol Pro?
Neither: both take 1.05M tokens.
How many benchmarks is the GPT-5.4 Pro vs GPT-5.6 Sol Pro comparison based on?
4 benchmarks have a result for both models as of October 22, 2026. GPT-5.4 Pro's coding index rests on 0 independent benchmarks and GPT-5.6 Sol Pro's on 0. Where only one model has a result, the page says so instead of naming a winner.