GPT-5.1 Chat
OpenAI · Mid
GPT-5.1 Chat (AKA Instant is the fast, lightweight member of the 5.1 family, optimized for low-latency chat while retaining strong general intelligence. It uses adaptive reasoning to selectively “think” on...
Input / 1M
$1.25
Output / 1M
$10.00
Cached input / 1M
$0.13
Context window
128K
Where it sits
218th-cheapest mid model
by blended $/Mtok among 262 listed mid models
502% above the mid median
blended $/Mtok across 262 mid models
Output costs 8× input
$1.25 in / $10.00 out per 1M
Cached input saves 90%
$0.13 vs $1.25 per 1M fresh
Held flat since launch (Jun 2026)
no blended price change recorded
Computed live from current prices and this model's history — not hand-written, so it stays accurate as prices move.
Price history
Only one price on record so far — the history chart appears once a price changes.
Snapshots
| Effective | Input | Output | Cached in | Note | Source |
|---|---|---|---|---|---|
| 11 Jun 2026 | $1.25 | $10.00 | $0.13 | Imported from OpenRouter | openrouter.ai |