title: "Fast AI Option: Live Corrections While You Type",

summary:

"How Fast AI improves your text as you type, the Corrections only switch, when it sends a change, its length limits, and how it counts toward your plan.",

category: "advanced-configuration",

tags: ["fast-ai", "fast-mode", "live-edit", "copy-edit", "latency"],

lastReviewed: "2026-10-18",

};

Fast AI Option: Live Corrections While You Type

Fast AI is DevSpeak's live editing mode. While you type, it improves your text in the language you wrote it in, fixing errors and making it read fluently, and shows the improved version next to your input, with every changed word underlined.

Fast AI does not write the technical spec. It keeps your meaning, your voice, your facts, and your layout. The full translation into a spec is still the job of the Translate button.

How to Enable Fast AI

Toggle the Fast AI control in the action cluster of the translation workspace. You need to be signed in. The output pane switches to the Fast AI · live edit view and starts correcting the text that is already in the input.

Pressing Translate turns Fast AI off and shows the full translation in the output pane.

Improve or Corrections Only

Fast AI has two modes, chosen with the Corrections only switch at the top of the pane:

  • Improve (switch off, the default) rewrites your text the way a careful editor would: it fixes every error, chooses the more natural word, harmonizes tenses, adds connectors, and splits or joins sentences where that reads better. It works paragraph by paragraph and never merges or reorders your lines.

  • Corrections only (switch on) fixes spelling, grammar, and punctuation and leaves everything else as you wrote it. It works sentence by sentence.

    • The same switch sits next to the Optimize button and applies to Optimize and to the Optimize output format too. DevSpeak remembers your choice on this browser.

    When a Correction Runs

    Fast AI only sends the paragraphs you changed (the sentences you changed, in Corrections only). A paragraph it has already improved is never sent again, even if you move it elsewhere in the text. Code blocks and tables are never sent: they stay exactly as you typed them, and so do inline code, links, and placeholders.

    | What you do | When Fast AI sends the change |

    | :--------------------------------------------- | :--------------------------------------- |

    | Type inside a sentence | After about half a second without typing |

    | Finish a sentence (., !, ?, or new line) | Almost at once |

    | Paste text | At once |

    | Change the audience, context, model, or mode | At once, for the whole text |

    On the Free plan without your own provider key, Fast AI waits for a finished sentence, a paste, or a longer pause (about one and a half seconds), because every correction uses the Free plan's daily Fast AI allowance.

    If you keep editing a sentence while its correction is still running, DevSpeak cancels the outdated request and sends the new version instead.

    How long each correction takes depends mainly on the model's response time, so DevSpeak does not publish a fixed figure.

    Reading the Result

  • Underlined words are the words Fast AI changed.

  • Dimmed text is still waiting for its correction.
  • Show changes also shows the removed words, struck through.
  • In Corrections only, click a corrected sentence to see up to two alternative phrasings. Pick one to replace that sentence.
  • Use this text replaces your input with the corrected text. You can undo it.

    • Length Limits

    | Input length | Behavior |

    | :---------------------- | :---------------------------------------------------------------------------------------------------- |

    | Up to 3,000 characters | Corrections appear as each sentence is ready |

    | 3,001–20,000 characters | A progress line shows how many paragraphs (or sentences) are done; the text fills in while you type |

    | Over 20,000 characters | Fast AI pauses and asks you to shorten the text, or to turn Fast AI off and use Translate instead |

    From 3,001 characters, the pane also shows a character counter against the 20,000-character limit.

    Usage and Limits

  • On the Free plan without your own provider key, Fast AI has its own allowance of 50 corrections and alternative requests a day, which resets at 00:00 UTC. It is separate from the Free plan's hourly request cap, so Optimize and Translate keep working when Fast AI pauses.

  • On paid plans, every correction and every request for alternatives counts toward the monthly managed token allowance, like any other request. With your own provider key, your provider bills the usage.
  • When a limit is reached, Fast AI pauses and says why. After a short-term limit or the daily Free allowance it resumes on its own; after the monthly allowance runs out, it stays paused.
  • Fast AI corrections are not saved to History. Only translations are.

    • Best Practices

  • Clean up first, then translate: let Fast AI fix the request, press Use this text, then press Translate for the full spec.
  • Review the underlines: a correction is a suggestion. Check the changed words before you apply them.
  • Use Translate for long documents: above 20,000 characters, or for attachments, use Translate or document translation instead.