As standard, avatars come with a pre-selected voice, but you can change the voice, language, and speed to fit your video needs.
Assign a Voice and Language
Use the Voice dropdown in the script box to choose a different voice and language for your avatar.
Select the speaker pill in the script box.
Select the voice you have currently and then choose Change Voice
You will then be in the Voice library:
Browse Featured voices (recommended picks) at the top.
Explore All voices across three tabs:
From Synthesia
My voices
and Shared with me
Search by name and filter by language or accent, or sort the list, to narrow down large voice catalogs.
Preview any voice, using the play icon on a voice row for a quick sample, or use the sticky preview bar at the bottom of the picker.
Then select the voice by clicking either the + button next to a voice option or the Swap Voice button in the selection bar.
A popup appears at the bottom of the screen, asking if you'd like to replace all instances of the voice in the video.
Click Change All to update the voice in all scenes
How to change voice speed
You can adjust the speed of your Avatar’s voice to better suit your video’s pacing.
💡 Want to keep viewers engaged and improve understanding? Slow down complex sections so people can absorb the information, and speed up repetitive parts to maintain momentum.
Hover over the speaker pill in the script box.
Use the slider to adjust the voice speed or enter the number in the Speed section
You have the option the choice of speeds between 0.8x (slower) and 1.2x (faster)
To apply this speed to all script blocks for the same Avatar and Voice, click Change all on the toast message that appears.
✍️ Voice speed adjustments only apply to voices provided by Synthesia, ElevenLabs, Google, IBM, or Microsoft Azure.
💡 Want to use your own voice? If you've created a Personal Voice, you can select it from the same menu. Learn more in How do I clone my voice in Synthesia?