Captions & Subtitles

VideoNest automatically generates closed captions for every video you upload. Captions are available on the video player, included in CTV feeds, and can be edited or supplemented with additional language tracks.

Automatic caption generation

Every video uploaded to VideoNest is automatically transcribed and a caption file is generated as part of the processing pipeline. You don't need to do anything — captions are ready by the time your video finishes processing. The generated file is available in both WebVTT (.vtt) and SRT (.srt) formats.

Auto-generated captions cover the primary audio track of your video. For accuracy, keep your audio clean and speech clearly audible. Captions are generated in the detected language of the audio.

Captions in the video player

When a video has captions, a CC button appears in the player controls. Viewers can toggle captions on or off at any time during playback. The player remembers the viewer's caption preference across sessions.

By default, captions are off — they must be actively enabled by the viewer. If you want captions to be on by default for a specific video or across your entire player, you can configure this in Player → Settings → Captions.

Uploading your own caption file

If you want to replace the auto-generated captions with a corrected or custom version, upload your own file. To upload a caption file:

1. Go to Media → Library and open the video
2. Select the Captions tab
3. Click Upload Caption File
4. Select your file — VideoNest accepts .vtt and .srt formats
5. Set the language for the track (e.g., English, Spanish)
6. Save — the uploaded file replaces or supplements the auto-generated track

Multiple language tracks

You can add caption tracks in multiple languages on the same video. Each language track is uploaded separately as a .vtt or .srt file with a language tag. When multiple tracks exist, the player shows a language selector inside the CC menu so viewers can choose their preferred language.

The auto-generated track is labeled with the detected language. Additional tracks you upload appear alongside it.

Downloading your caption file

You can download the auto-generated or uploaded caption file at any time from the Captions tab on any video. This is useful for editing captions externally or submitting them to a translation service before re-uploading.

Captions in CTV and podcast feeds

Caption files are included in your VideoNest feeds automatically. Platforms that require captions — including Amazon Fire TV, Roku, Tubi, and Apple TV — receive them in the appropriate format:

If a video does not have captions and the destination platform requires them, VideoNest will flag the video in your feed dashboard. Tubi, Amazon Fire TV, and Roku require captions on all content — videos without captions will be excluded from those feeds until captions are added.

Accepted video formats

VideoNest accepts all common video file formats for upload. Caption generation works on all supported formats:

If you're unsure whether your format is supported, MP4 (H.264) is the recommended format for the most reliable processing and delivery.

Upload limits

You can upload up to 25 videos or 50 GB in a single batch. For larger batches, split your upload into multiple sessions or use cloud storage import for very large libraries.

Total storage on the standard plan is 300 GB. If you need more, contact the VideoNest team — custom storage limits are available.