speed.md +13 −6
5Codex offers the ability to increase the speed of the model for increased5Codex offers the ability to increase the speed of the model for increased
6credit consumption.6credit consumption.
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88Fast mode is currently supported on GPT-5.4. When enabled, speed is increasedFast mode increases supported model speed by 1.5x and consumes credits at a
99by 1.5x and credits are consumed at a 2x rate.higher 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.
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1113Enable it by typing `/fast`. It is available in Codex IDE Extensions, CodexUse `/fast on`, `/fast off`, or `/fast status` in the CLI to change or inspect
1214CLI, and the Codex app.the current setting. You can also persist the default with `service_tier = "fast"` plus `[features].fast_mode = true` in `config.toml`. Fast mode is
15available in the Codex IDE extension, Codex CLI, and the Codex app when you
16sign in with ChatGPT. With an API key, Codex uses standard API pricing instead
17and you can't use Fast mode credits.
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15Your browser does not support the video tag.20Your browser does not support the video tag.
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18## Codex-Spark23## Codex-Spark
19 24
2025GPT-5.3-Codex-Spark is a separate fast, less-capable Codex model optimized for near-instant, real-time coding iteration. Unlike fast mode, which speeds up GPT-5.4 at a higher credit rate,GPT-5.3-Codex-Spark is a separate fast, less-capable Codex model optimized for
2126Codex-Spark is its own model choice and has its own usage limits.near-instant, real-time coding iteration. Unlike fast mode, which speeds up a
27supported model at a higher credit rate, Codex-Spark is its own model choice
28and has its own usage limits.
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23During research preview Codex-Spark is only available for ChatGPT Pro subscribers.30During research preview Codex-Spark is only available for ChatGPT Pro subscribers.