GPT-5.5
Knows up to December 2025Missing 1,962 events
gpt-5.5
$5 in, $30 out per 1M tokens
GPT-5.4
Model idgpt-5.4
Price$2.50 in, $15 out per 1M tokens
Checked29 September 2026
Knows up to August 2025
2,002events after its cutoff
87 historic, 461 major. 439 days of news.
It launched on 5 March 2026, already missing 86 of them. Coverage before 2026 is thin (80 entries for 2025), so this count is a floor.
Five things it has never heard of
Its cutoff, August 2025, is before this chart starts: every mark here is news it has never seen.
How to call it
4 ways to use GPT-5.4, with the model id each provider expects.
| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| OpenAI API | gpt-5.4 |
https://api.openai.com/v1/responses |
developers.openai.com |
| Azure OpenAI (Microsoft Foundry) | gpt-5.4 |
learn.microsoft.com | |
| OpenRouter | openai/gpt-5.4 |
openrouter.ai | |
| Web app | chatgpt.com |
Pricing
| Input | $2.50 per 1M tokens |
|---|---|
| Cached input | $0.25 per 1M tokens |
| Output | $15 per 1M tokens |
As published: “per 1M tokens (USD), standard tier”. Note: prompts >272K input tokens billed 2x input / 1.5x output.
Source: developers.openai.com, checked 29 September 2026.
Specs
- Input
- Text and images
- Output
- Text
- Context window
- 1,050,000 tokens
- Max output
- 128,000 tokens
- Open weights
- No
- Licence
- Proprietary
- Training cutoff
- August 2025
- Released
- 5 March 2026
- Status
- Legacy
- Type
- Reasoning model
What stands out
What its maker marketed at launch, and what people found later, each with its source.
Tool search and computer use
Launched together with API tool search and computer-use support.
1M context
1.05M context window with 128K output; effort defaults to none.
Four assistants, one scale
GPT-5.4 is added as a fifth row. Each row runs from what the model knows (graphite) through the months between its cutoff and its launch (hatched) to today (pink).
- GPT-6 Astra 271 at launch, 1,863 today
- Claude Opus 5.5 372 at launch, 1,795 today
- Gemini 4 Hydrogen 1,863 at launch, 1,889 today
- Grok 4.7 387 at launch, 1,829 today
- GPT-5.4 86 at launch, 2,002 today
Show as a table
| Model | Cutoff | Released | Missing at launch | Missing today |
|---|---|---|---|---|
| GPT-6 Astra | April 2026 | 3 September 2026 | 271 | 1,863 |
| Claude Opus 5.5 | June 2026 | 22 September 2026 | 372 | 1,795 |
| Gemini 4 Hydrogen | March 2026 | 12 November 2026 | 1,863 | 1,889 |
| Grok 4.7 | May 2026 | 21 September 2026 | 387 | 1,829 |
| GPT-5.4 | August 2025 | 5 March 2026 | 86 | 2,002 |
Notes
Snapshot gpt-5.4-2026-03-05. Variants gpt-5.4-pro ($30/$180), gpt-5.4-mini ($0.75/$4.50), gpt-5.4-nano ($0.20/$1.25) are also on the pricing page and OpenRouter.
curl https://api.openai.com/v1/responses \
-H "Authorization: Bearer $OPENAI_API_KEY" -H "Content-Type: application/json" \
-d '{"model":"gpt-5.4","input":"Hello"}'
Sources: