AI API PricesOpenAI › GPT-5.5

GPT-5.5 pricing

GPT-5.5 API cost from OpenAI — $5.00 per 1M input tokens and $30.00 per 1M output tokens. Flagship. Estimate your real monthly bill below, then compare it against every other model.

Input price
$5.00
per 1M input tokens
Output price
$30.00
per 1M output tokens
Cached input
$0.500
per 1M · ~90% off input
Reference call
$0.035
1K in + 1K out

Flagship 400K context · all prices USD per 1M tokens, list price last verified 2026-06-27.

GPT-5.5 capabilities & limits

Representative specs for this tier — confirm exact limits in the OpenAI docs.

Context window400K
Max output64K
Knowledge cutoffSep 2025
API formatOpenAI-compatible
✓ Vision✓ Tools / functions✓ JSON / structured✓ Prompt caching✓ Batch API

API acting up? Check live OpenAI status → · all AI API status

Call GPT-5.5 from your code

The exact model string and endpoint to use. Works with the OpenAI SDK — just point base_url at the URL below.

Model stringgpt-5.5
Base URLhttps://api.openai.com/v1
API key envOPENAI_API_KEY
curl https://api.openai.com/v1/chat/completions \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.5",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Model strings follow each provider's naming convention; confirm the current id in the OpenAI docs before relying on it.

What a GPT-5.5 API call actually costs

Blended input + output cost at GPT-5.5's list rates — useful yardsticks before you commit to volume.

$0.035
Short call
1K in · 1K out
$0.030
Chat turn
3K in · 500 out
$0.130
RAG / long prompt
20K in · 1K out
$35.00
1M in + 1M out
bulk job

GPT-5.5 cost calculator

Enter your monthly volume to estimate the GPT-5.5 bill. Runs entirely in your browser.

Estimated monthly cost

For the full multi-model breakdown, use the cost calculator.

OpenAI models — GPT-5.5 in context

How GPT-5.5 prices against its siblings. Cheapest reference cost first.

Model Input /1M Output /1M Cost / call* Context Type
GPT-5.4 nano
Cheapest OpenAI tier
$0.200 $1.25 $0.0015 400K Fast / cheap
GPT-5.4 mini $0.750 $4.50 $0.0053 400K Balanced
GPT-5.6 Luna
Cheapest GPT-5.6 · budget frontier
$1.00 $6.00 $0.0070 400K Balanced
GPT-5.6 Terra
Daily driver · ½ the cost of GPT-5.5
$2.50 $15.00 $0.017 400K Flagship
GPT-5.4
Balanced flagship
$2.50 $15.00 $0.017 400K Flagship
GPT-5.6 Sol
New flagship · limited preview
$5.00 $30.00 $0.035 400K Flagship
GPT-5.5
Flagship
$5.00 $30.00 $0.035 400K Flagship

*Reference cost of one call with 1,000 input + 1,000 output tokens — a neutral yardstick. Use the calculator for your real usage. Cheapest row highlighted.

Cheaper than GPT-5.5? In the same flagship tier, MiniMax-M3 runs $0.300 in / $1.20 out. The overall cheapest model tracked is Gemini 1.5 Flash-8B — see the cheapest LLM API guide.

How GPT-5.5 pricing works

GPT-5.5 is billed per token: a lower input price of $5.00 per million tokens for everything you send, and a higher output price of $30.00 per million for everything the model generates. To turn that into a real GPT-5.5 bill, multiply by your monthly request volume and average prompt/response length — the calculator above does exactly that.

Prompt caching is the biggest lever on your GPT-5.5 cost: cached input tokens bill at just $0.500 per million — about 90% cheaper. If you reuse a long system prompt or context across calls, caching can dramatically cut the input portion of your bill.

List prices move fast — always confirm the current numbers on the official OpenAI pricing page before relying on them for budgeting.

GPT-5.5 pricing FAQ

How much does the GPT-5.5 API cost?

GPT-5.5 costs $5.00 per 1M input tokens and $30.00 per 1M output tokens, with cached input at $0.500 per 1M (about 90% off). A typical 3K-input / 500-output call works out to about $0.030.

What is GPT-5.5's context window?

GPT-5.5 has a 400K-token context window. Tokens you put in the prompt are billed at the $5.00 per 1M input rate.

Does GPT-5.5 support prompt caching?

Yes. GPT-5.5 bills cached input tokens at $0.500 per 1M instead of $5.00 — roughly 90% cheaper for the repeated part of your prompts.

Is there a cheaper alternative to GPT-5.5?

In the same flagship tier, MiniMax-M3 (MiniMax) is cheaper at $0.300 in / $1.20 out. The overall cheapest model on the market is Gemini 1.5 Flash-8B.

Compare GPT-5.5 with other models