Blog / Product

Dictate Your Prompts with Voice Input

You can speak your prompts to Mythex instead of typing them. Click the microphone or press Alt+V, check the text, and send. How it works and its limits.

Mythex Team · 2026-09-29 · 3 min read

You can talk to Mythex instead of typing. The composer has a microphone button: click it (or press Alt+V, Option+V on a Mac), say what you want, and your words appear as text in the message box. You read it over, fix anything that came out wrong, and send it like any other prompt.

What it does

Voice input turns speech into the text of your prompt. It uses your browser's built-in speech recognition, so there is nothing to install and no separate app to open.

It works in the composers that use Mythex's shared prompt bar. That means the chat inside a project workspace, and the home composer where you start a new project, since it uses the same control.

The transcribed words land in the message box. Nothing is sent until you send it, so you always get a chance to read what was heard before the agent acts on it.

Why we built it

Describing an app is often easier out loud than on a keyboard. Most people explain an idea more naturally by talking it through: "a booking page for a barbershop, three barbers, customers pick a time, I get an email." Typing the same thing tends to come out shorter and vaguer, and a vague prompt gets a vaguer first draft.

It also helps when typing is the slow part — on a laptop you're using one-handed, when your hands are busy, or when you simply think faster than you type. And it's useful while you look at the preview: you can describe what you see ("the button on the pricing card is cut off") without moving your eyes back and forth to type.

How to use it

  1. Open a project, or go to the home composer to start a new one.
  2. Click the microphone in the composer, or press Alt+V (Option+V on a Mac). The shortcut does the same thing as the button: it starts dictation, and pressing it again stops it.
  3. Allow microphone access the first time your browser asks. Without it, the browser can't hear you.
  4. Say one clear goal. For example: "Add a contact form to the about page with name, email and message fields."
  5. Stop dictation with the button or Alt+V again.
  6. Read the text and fix it. Speech recognition mishears names, technical words and punctuation. Edit the message box directly before you send.
  7. Send as usual.

Tips for good spoken prompts

Voice changes how you enter a prompt, not what makes a prompt good. The same advice applies:

  • One goal per message. It's tempting to keep talking once you've started. A list of five changes in one breath is harder to act on — and harder to check afterwards — than five short messages.
  • Say what should stay the same. "Change the colours, keep the layout" is clearer than "change the colours".
  • Describe what you see. Point at a specific page or part of the preview rather than the app in general.
  • Spell out the words that matter. Product names, brand names and unusual terms are the most likely to be misheard. Check them before you send, or type those parts.
  • Edit, don't re-record. If one word is wrong, fixing it in the message box is quicker than dictating the whole thing again.

Our guide on how to write prompts for AI app builders goes further on phrasing.

What it doesn't change

Voice is a convenience for prompting, and nothing more:

  • It doesn't change your mode. If you're in Build, Plan or Ask, a dictated prompt is handled exactly as a typed one would be. Pick the mode the same way you normally do.
  • It doesn't change credits. A spoken prompt costs the same as the same prompt typed.
  • It doesn't send on its own. You always see the text first.

Limits

  • It depends on your browser's speech recognition. Voice uses the browser speech API, so how well it works — and whether it's available at all — comes down to the browser you use.
  • It only appears where the shared prompt bar is used: the project workspace chat and the home composers built on the same control.
  • Microphone permission is required. If you said no when the browser asked, dictation can't start. Re-enable the microphone for mythex.ai in your browser's site settings and try again.
  • Transcription isn't perfect. Treat the text as a draft and read it before sending.

Get started

Next time you open a project, click the microphone, or press Alt+V, and describe the next change you want in a sentence or two. If the result isn't what you meant, you can always roll back with a checkpoint and try again.

The docs page is short and covers the details: Voice input.

Keep reading

  • A Landing Page for Every Kind of Business — Search for a booking system for a dental clinic or a website for a bakery and land on a Mythex page written for that business, with a prompt ready to build it.
  • A Private Workspace and a Live Preview for Every Project — Every Mythex project runs in its own private cloud workspace with a live preview beside the chat. How it works, how to use it, and what to expect.
  • Auto-Reload: Keep Your Published App Running When Credits Run Low — Auto-reload buys Mythex credits when your balance runs low, so a long build or a busy published app does not stop at zero. How to set it up, and its limits.
  • Build Mythex Apps from Claude, Cursor or Codex — Mythex runs a remote MCP server: connect Claude, Cursor or Codex, and they code in your Mythex cloud sandbox with a live preview, database and publishing.
  • Checkpoints: Undo Any Change the Agent Makes — After every successful turn, Mythex saves a checkpoint of your project. Revert to any of them in two clicks, or edit an earlier message and try again.
  • Connect Gmail, Google Sheets and Slack to Your App Builder — Mythex Connectors link Gmail, Google Sheets, Slack, Notion and more to the chat agent, with no API keys in your code. How it works, setup, and limits.

Start building free · Templates · Docs