Subtitle burn-in safe-zone studio

Burn SRT or WebVTT captions into a WebM video locally.

On your device · No account

Privacy details

Subtitle burn-in safe-zone studio processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

Choose a VP8 or VP9 WebM

Plain SRT or WebVTT subtitles

Text size, margin and format limits

Text size (pixels)

Inset from image edges (%)

White text with a black outline. Two lines per cue; no overlapping cues or markup. The inset is your chosen layout margin, not a platform safe-zone guarantee. Finalized VP8/VP9 WebM only; MP4 is not supported.

Captioned video

Preparing example…

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

Keyboard shortcuts

Updated 2026-09-20

Create and preview the edited video

Paste timed plain subtitles and choose Burn in subtitles. White text with a black outline is drawn only during each cue. The inset is an editable layout choice, not a promise about any platform’s controls or crops. Audio and duration are retained.

A worked example

In the example, Hello appears during the first half-second and Again during the second half-second.

Next: Video frame extractor

Before you use the result

Finalized VP8/VP9 WebM only, up to 100 MB, five minutes, 1800 frames and 150 million output frame pixels. No MP4. Two plain lines per cue; no overlapping cues, styling markup or cues beyond the clip. Even dimensions and WebCodecs are required. Output is lossy VP8 WebM with permanent captions. Use ordinary 8-bit SDR footage; HDR and wide-gamut metadata are rejected. Supported SDR matrix/range metadata is carried into decoding and the encoded output.

Next: Subtitle converter

Cite this page

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ToolOctopus. “Subtitle burn-in safe-zone studio.” Updated 2026-09-20. https://tooloctopus.com/subtitle-burn-in-safe-zone-studio.

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