GPT-5.5
The previous-generation high-end model, still a capable and widely-deployed choice before GPT-6. Reliable for demanding reasoning and coding where teams have not yet migrated.
At a glance
Released
Feb 10, 2026
Provider
OpenAI
Context window
500,000 tokens
Max output
64,000 tokens
Modalities
Text + image → text
Knowledge cutoff
October 2025
API model ID
gpt-5.5License
Proprietary (API only)
Pricing
Standard
Input$5 / 1M
Output$30 / 1M
Batch (50% off)
Input$2.50 / 1M
Output$15 / 1M
A typical 1,500-token prompt with a 650-token answer costs ≈ $0.027 on the standard tier. Run your own prompt through the calculator →
What's new vs the previous model
Compared withGPT-5 (August 2025)
- Stronger reasoning and coding than GPT-5
- Better long-context handling
- Improved reliability on agentic tasks
- Superseded by the GPT-6 generation
- Older knowledge cutoff than GPT-6 models
Best use cases
Established workloads
Powers apps built before GPT-6 without a migration.
Reasoning and coding
Handles complex technical tasks competently.
General assistant
Serves broad chat and generation needs.
Strengths & limitations
Strengths
- Proven capability
- Good reasoning
- Multimodal
- Mature tooling
Limitations
- Older cutoff
- Outclassed by GPT-6 flagships
How to test it
- No-code: open chatgpt.com and pick GPT-5.5 from the model switcher — no API key needed.
- Playground: sign in to the OpenAI Platform and run prompts in the workbench, then copy the generated code.
- API: create a key in the OpenAI Platform and call the API (example below).
curl https://api.openai.com/v1/chat/completions \
-H "Authorization: Bearer $API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.5",
"messages": [{"role": "user", "content": "Explain tokenization in one paragraph."}]
}'