GPT-5.5 API pricing
Official OpenAI list price, last checked Oct 29, 2026. Updated Oct 29, 2026.
GPT-5.5 costs $5 per 1M input tokens and $30 per 1M output tokens, cached input at $0.50, per OpenAI's official pricing page (checked Oct 29, 2026). It's a premium-priced model: number 75 of 77 by blended price ($11.25 per 1M tokens at a 3 to 1 input to output mix). On LMArena's Code Arena it ranks #37 of 50 models we price (relative score 0 out of 100). Cheaper pick: Claude Sonnet 5.5 scores 85 against 0 on the same board at $4 blended, 2.8x less.
GPT-5.5 price per million tokens
| GPT-5.5 price per million tokens | USD |
|---|---|
| Input | $5 |
| Cached input | $0.50 |
| Output | $30 |
| Blended, 3 parts input to 1 part output | $11.25 |
| Context window | Not listed |
Official note from OpenAI: Prompts up to 272K.
What GPT-5.5 costs for real work
List-price estimates for a month, no discounts. Our math, not a quote: change the token counts in the plan vs API calculator.
| Workload | Tokens a month | GPT-5.5 | Claude Opus 5.5 | Claude Sonnet 5.5 |
|---|---|---|---|---|
| Light: a side project or personal assistant | 2M in, 0.5M out | $25.00 | $18.00 | $9.00 |
| Medium: a small team or one product feature | 20M in, 5M out | $250 | $180 | $90.00 |
| Heavy: a production app | 200M in, 50M out | $2,500 | $1,800 | $900 |
| Medium with 80% of input cached | 20M in (16M cached), 5M out | $178 | $119 | $59.60 |
How GPT-5.5 ranks on LMArena
Relative score: 100 is the top model we price on that board. Rank is among the models in our price table, not the full leaderboard.
| Board | Rank | Score /100 |
|---|---|---|
| Coding (Code Arena) | #37 of 50 | 0 |
| Chat (Text Arena) | #12 of 51 | 27 |
| Creative writing (Text Arena creative writing) | #16 of 51 | 8 |
| Roleplay and characters (Text Arena multi-turn) | #11 of 51 | 18 |
| Reasoning and math (Text Arena math) | #11 of 51 | 44 |
| Vision (Vision Arena) | #9 of 33 | 69 |
| Long documents (Document Arena) | #4 of 11 | 89 |
Closest rivals to GPT-5.5
The models nearest in price, other makers first. Ranks are on Code Arena, where we have them.
| Model | In / out | Blended | Verdict |
|---|---|---|---|
| Claude Opus 5.5 | $4 / $20 | $8 | Claude Opus 5.5 wins on both. Compare |
| Muse Wonder 1.0 | $4 / $20 | $8 | Muse Wonder 1.0 wins on both. Compare |
| Kimi K3.1 Pro Highspeed | $4 / $20 | $8 | Kimi K3.1 Pro Highspeed wins on price. Compare |
| Claude Fable 5.1 | $10 / $50 | $20 | Claude Fable 5.1 for quality, GPT-5.5 for price. Compare |
Cheaper alternatives to GPT-5.5
At least 40% cheaper blended, best LMArena score first.
| Model | In / out | Blended | Verdict |
|---|---|---|---|
| Claude Sonnet 5.5 | $2 / $10 | $4 | Claude Sonnet 5.5 wins on both. Compare |
| GPT-6.1 Sol | $2 / $10 | $4 | GPT-6.1 Sol wins on both. Compare |
| Kimi K3.1 Pro | $2 / $10 | $4 | Kimi K3.1 Pro wins on both. Compare |
More from OpenAI
- GPT-5.6 Sol$4 in, $20 out per 1M
- GPT-5.6 Terra$2 in, $12 out per 1M
- GPT-6.1 Sol$2 in, $10 out per 1M
- GPT-6 Sol$2 in, $10 out per 1M
- GPT-6 Astra$10 in, $50 out per 1M
FAQ
How much does the GPT-5.5 API cost per million tokens?
$5 per 1M input tokens and $30 per 1M output tokens, plus $0.50 per 1M for cached input, as of Oct 29, 2026. A typical 3 to 1 input to output mix works out to $11.25 per 1M tokens.
Does GPT-5.5 charge more for long prompts?
OpenAI doesn't list a long-prompt surcharge for GPT-5.5. Its pricing note says: Prompts up to 272K.
Is GPT-5.5 cheaper than Claude Opus 5.5?
No. A medium month (20M input and 5M output tokens) costs $250 on GPT-5.5 and $180 on Claude Opus 5.5 at list price. On Code Arena, GPT-5.5 ranks #37 and Claude Opus 5.5 #1.
How does GPT-5.5 rank on LMArena?
On Code Arena it is #37 of 50 models we price, with a relative score of 0 out of 100. It ranks on 7 of 8 boards we track.
What is a cheaper alternative to GPT-5.5?
Claude Sonnet 5.5 costs $2 in and $10 out per 1M tokens, about 2.8x less blended, and scores 85 on Code Arena against 0 for GPT-5.5.
Where does this GPT-5.5 price come from?
From OpenAI's official pricing page, which we check every day. This page was last checked Oct 29, 2026.