Text-to-Speech (TTS)

What is text-to-speech?

Text-to-speech enables you to listen to virtually any document using the highest quality AI voices the big tech companies have to offer. Note that text-to-speech only works on PDFs in text view. You can still start TTS playback while in original PDF view, but doing so will automatically switch the document to text view.

How do I start text-to-speech (TTS) partway through a document?

You can start the TTS from your current scrolled position by tapping the play button in the top right corner.

This will start the TTS at whichever paragraph is roughly centered on your screen when you start it.

What's the difference between pausing and stopping the text-to-speech?

You can pause the current playback using the pause button in the middle of the playback control bar. This will keep the playback control bar active and remember your place, so you can resume playback when you're ready.

Pause text-to-speech from the audio control bar.

You can stop the TTS playback of the current document by tapping the square stop icon in the top right.

This will cancel the TTS playback of the current document and hide the control bar. If you wish to resume the document after stopping TTS, you'll need to relocate where you ended and restart TTS playback using the play button.

How do I highlight while listening to a document using text-to-speech? Can I triple tap my AirPods?

Yes! To enable highlighting via triple tap, navigate to Account settings and then to Headphone gestures. By default, double tap is set to Jump forward and triple tap is set to Jump backward, but you can change either (or both) of these gestures to highlight instead.

Why does it sometimes stop automatically scrolling along with the TTS? How can I make it follow the speech again?

When Reader detects scrolling input from the user, it will stop automatically following the text-to-speech highlighting so as not to cause a frustrating experience where you're trying to scroll somewhere and it keeps forcibly jumping you back to the highlighted text.

If you scroll away from the current playback location, the 15s back/forward buttons on the playback bar will be replaced with return and jump buttons. Tapping return will scroll you back to where the TTS is currently reading.

Return button on TTS playback bar in Reader.

Once you've returned, it will go back to following along with the text-to-speech until you scroll away again.

Use the return button to go back to your TTS position.

Can I jump the text-to-speech playback to a different part of the document?

If you scroll away from the current text-to-speech playback location, the 15s back/forward buttons on the playback bar will be replaced with return and jump buttons. Tapping jump will stop the current playback and start it back up at the location currently centered on your screen.

Use the jump button to change your current TTS playback position.

Note that, depending how far from your previous location you've moved, there may be a brief period of loading (like when you first start TTS playback) as Reader generates speech for the new section of the document.

Does text-to-speech work on languages other than English?

Yes! To change the language while listening, first tap on the waveform icon at the left side of the TTS bar.

Then tap View all languages at the bottom of the menu.

View non-English languages for text-to-speech.

How do I use text-to-speech offline?

Currently, it's not possible to use text-to-speech offline, since the speech is generated on request to allow for quicker playback and better performance. Eventually, we may look into adding the option to pre-download the TTS for a document before going offline.

How do I use text-to-speech in the web app?

You can start using text-to-speech in the web app by clicking the Listen button in the top right, above the document's title. You can also use the Command Palette (cmd/ctrl + K) to search for tts and start playback from any point in the document.

Can I use keyboard shortcuts to control TTS?

The web app has a full set of keyboard shortcuts to control TTS playback. P will play or pause, shift + P will stop playback, left arrow and right arrow will skip through the content, and shift + up arrow or shift + down arrow will control the volume. The built-in media controls on your keyboard will also work for this. To slow the speed of playback, press ,, and to speed it up, press ..