GPT-5.5 Pro vs GPT-5 Pro
GPT-5 Pro costs 1.5x less per output token than GPT-5.5 Pro ($120.00 vs $180.00 per million). Updated October 21, 2026; 7 benchmarks have a result for both.
GPT-5.5 Pro or GPT-5 Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GPT-5.5 Pro for a larger context window (1.05M against 400K tokens).
- Shared results
- 7
- GPT-5.5 Pro only
- 2
- GPT-5 Pro only
- 1
- 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
GPT-5.5 Pro
GPT-5.5 Pro takes 1.05M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5 Pro
GPT-5.5 Pro $0.120, GPT-5 Pro $0.075 per turn.
List prices
At a glance
- Coding index
- GPT-5.5 Pro not benchmarked, GPT-5 Pro not benchmarked.
- Widest category
- Math, 45.2 points apart on average over 2 shared benchmarks.
- Widest single gap
- ARC-AGI-2: GPT-5.5 Pro 84.6% against GPT-5 Pro 18.3%, 66.3 points apart on a 0 to 100 scale.
- Output price
- GPT-5.5 Pro $180.00 against GPT-5 Pro $120.00 per million output tokens, 1.5x apart.
- Context window
- GPT-5.5 Pro takes 1.05M tokens, GPT-5 Pro 400K.
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-5.5 Pro | Bars | GPT-5 Pro | Ties |
|---|---|---|---|---|
| Intelligence | 1 | 0 | ||
| Reasoning | 4 | 0 | ||
| Math | 2 | 0 | ||
| All shared boards | 7 | 0 |
CodingDirectional onlySix of these boards feed the Vibe Coding Index1 board, none shared
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| WeirdML | Not measured | 60.4% | Only GPT-5 Pro measured |
| Neither model has a result on the other 37 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 162.9 | 150.6 | GPT-5.5 Pro |
| Neither model has a result on the other 1 board here | |||
Agentic workNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| Neither model has a result on 39 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| ARC-AGI | 96.5% | 70.2% | GPT-5.5 Pro |
| ARC-AGI-2 | 84.6% | 18.3% | GPT-5.5 Pro |
| SimpleBench | 76.9% | 61.6% | GPT-5.5 Pro |
| Chess puzzles | 62.0% | 48.0% | GPT-5.5 Pro |
| Neither model has a result on the other 17 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| FrontierMath, tiers 1 to 3 | 87.7% | 55.8% | GPT-5.5 Pro |
| FrontierMath, tier 4 | 78.0% | 19.5% | GPT-5.5 Pro |
| Neither model has a result on the other 11 boards here | |||
KnowledgeNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.5 Pro | GPT-5 Pro | Leader |
|---|---|---|---|
| Neither model has a result on 17 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.5 Pro | GPT-5 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-5.5 Pro | GPT-5 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 Pro costs less
Repository review
50K input + 3K output tokens
GPT-5 Pro costs less
Agent loop
200K input + 10K output tokens
GPT-5 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-5.5 Pro | OpenAI GPT-5 Pro |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | April 24, 2026 | October 6, 2025 |
| Context window | 1.05M | 400K |
| Input $/Mtok | $30.00 | $15.00 |
| Output $/Mtok | $180.00 | $120.00 |
| 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-5.5 Pro better than GPT-5 Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GPT-5.5 Pro for a larger context window (1.05M against 400K tokens).
Which is cheaper, GPT-5.5 Pro or GPT-5 Pro?
GPT-5.5 Pro costs $30.00 per million input tokens and $180.00 per million output tokens; GPT-5 Pro costs $15.00 and $120.00. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5.5 Pro or GPT-5 Pro?
GPT-5.5 Pro, with 1.05M tokens against 400K.
How many benchmarks is the GPT-5.5 Pro vs GPT-5 Pro comparison based on?
7 benchmarks have a result for both models as of October 21, 2026. GPT-5.5 Pro's coding index rests on 0 independent benchmarks and GPT-5 Pro's on 0. Where only one model has a result, the page says so instead of naming a winner.