speed.md +32 −0 added
1# Speed
2
3## Fast mode
4
5Codex offers the ability to increase the speed of the model for increased
6credit consumption.
7
8Fast mode increases supported model speed by 1.5x and consumes credits at a
9higher rate than Standard mode. It currently supports GPT-5.5 and GPT-5.4,
10consuming credits at 2.5x the Standard rate for GPT-5.5 and 2x the Standard
11rate for GPT-5.4.
12
13Use `/fast on`, `/fast off`, or `/fast status` in the CLI to change or inspect
14the current setting. You can also persist the default with `service_tier =
15"fast"` plus `[features].fast_mode = true` in `config.toml`. Fast mode is
16available in the Codex IDE extension, Codex CLI, and the Codex app when you
17sign in with ChatGPT. With an API key, Codex uses standard API pricing instead
18and you can't use Fast mode credits.
19
20<VideoPlayer
21 src="/videos/codex/fast-mode-demo.mp4"
22 class="[&_video]:mx-auto [&_video]:max-h-[400px] [&_video]:max-w-full [&_video]:w-auto"
23/>
24
25## Codex-Spark
26
27GPT-5.3-Codex-Spark is a separate fast, less-capable Codex model optimized for
28near-instant, real-time coding iteration. Unlike fast mode, which speeds up a
29supported model at a higher credit rate, Codex-Spark is its own model choice
30and has its own usage limits.
31
32During research preview Codex-Spark is only available for ChatGPT Pro subscribers.