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We ran 153 autonomous runs across 18 frontier models on the nanoGPT optimizer speedrun.
Elie Bakouch
GPT-5.5
A new class of intelligence for coding and professional work.
Specs
Model
- Family
- GPT-5
- Variant
- 5.5
- Weights
- Proprietary
Limits
- Context
- 1,050,000 tokens
- Max output
- 128,000 tokens
Modalities
- Input
- Text Image PDF
- Output
- Text
Pricing
- Input
- $5 / 1M
- Output
- $30 / 1M
- Cache read
- $0.5 / 1M
Capabilities
- Reasoning
- Yes
- Reasoning control
- Effort levels
- Tool calling
- Yes
- Attachments
- Yes
Dates
- Released
- 23 Apr 2026
- Knowledge cutoff
- 1 Dec 2025
Articles
All articlesprimeintellect.ai
Random list of tips (ymmv) from trying to get gpt 5.5 to build a big thing over a day or two
gfodor.id@gfodor
Introducing GPT-5.5
A new class of intelligence for coding and professional work.
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