Independent text-to-speech segments
Choose a voice for each passage and generate its speech and captions together. Completed passages become compact list items. Edit an item in place or write the next passage in the input below the list.
Add Voiceover to Video
Add AI narration to an existing video with text to speech. Write separate passages, set their start times, generate subtitles, and download your narrated MP4.
How to use
How to add a voiceover to your video
Turn written narration into speech for an existing clip. Add one passage or build a sequence of independently timed segments.
Choose your video
Upload or drop an MP4, WebM, or MOV from your device. Preview the clip and decide where an explanation would help. Your source video stays in the browser.
Write and generate a narration
Enter a passage in the input below the video and choose a voice. Sign in with a verified account to generate speech and subtitles. The finished narration becomes a list item, leaving a new input below it for the next passage.
Place each segment on the video
Edit any narration in its own row. Open its settings and drag the start-time slider to move the video preview to that moment. Listen to the full passage and adjust its timing so it fits the scene.
Preview and download
Use Video settings to balance the original sound and show or hide subtitles. When every narration fits, open Export to download an MP4 or the captions as an SRT file. Save your downloads before leaving the page.
Narration controls
Build a voiceover one segment at a time
Keep each explanation separate so you can adjust the voice, wording, and start time for one scene without recreating every narration.
Timing linked to the video preview
Open a narration’s settings and drag its start-time slider. The preview moves to that point immediately, helping you place the explanation beside the right action. Play the clip to check the full result.
Video and subtitle downloads
Keep, lower, or mute the original sound in Video settings. Show captions on the video or download a separate SRT file. The MP4 combines your footage with the generated narration.
Use cases
Give existing footage a clear spoken explanation
Write narration around what is already happening on screen, from a recorded tutorial to a silent animation.
Screen recordings and tutorials
Explain each click or step with a short passage. Set its start time near the action so viewers hear the instruction while they can see the relevant control.
Product demonstrations
Introduce the product, explain a feature, and close with a next step. Separate segments make it easier to revise one product detail or change the voice for a section.
Lessons and animated diagrams
Add spoken context to whiteboard animations, slide videos, or demonstrations. Leave pauses for viewers to inspect the image and use captions to support the narration.
Before you export
Make the narration fit the scene
The source video keeps its original length. Plan each passage around the time available on screen.
Write for the available time
Use one clear point per passage and preview the generated speech. If a segment runs past the end, shorten its wording and regenerate it or move its start time earlier.
Listen for overlap
Segments that overlap play together. Space them apart for a single narrator, and lower the original audio when background speech makes the new narration hard to hear.
Review captions and save the result
Check the preview with subtitles enabled, then download the MP4 and any SRT file you need. This editor does not save a project when you refresh or leave the page.
Voiceover and subtitle FAQ
Choose a video, write your narration underneath the preview, select a voice, and generate speech and subtitles. Set the start time for each segment, preview the result, and export an MP4.
Yes. Write a narration in the bottom input and generate it. Finished narrations become compact list items, and a new input stays below the list. Use the pencil icon to edit a narration in its original position, or its menu to delete it. Each narration keeps its own voice, timing, audio, and subtitles. Editing or retrying one leaves the others intact. Overlapping narrations play together.
Yes. Open Video settings next to the + menu to keep, lower, or mute the original audio. The preview and exported video use the same volume.
Yes. Open Export to download the captions as an SRT file or the video as an MP4. Toggle visible subtitles in Video settings. Subtitle times follow the start time of each narration segment.
The source video and final video rendering stay in your browser. Narration text is sent to our speech provider, and generated audio is stored and processed for subtitles. Sign in with a verified account to generate. This editor is not saved to project history; download your work before leaving or refreshing.
The editor shows a timing warning and blocks export. Move that segment earlier or shorten its text and generate it again. Videos keep their original duration.
Choose an MP4, WebM, or MOV file up to 250 MB that your browser can play. Export requires browser support for video encoding. The editor keeps the original video duration.
Open the settings for that narration and drag the start-time slider. The video preview moves to the selected moment immediately. Then play the clip to check the speech against the action. Changing the start time also moves that segment’s subtitles.
The generated subtitles belong to the new narration you write. This workflow does not transcribe the source video’s existing soundtrack or automatically translate it.
Continue creating with NarraCut
Choose the next tool for your workflow. Download your current result before opening another editor.
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