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Guides2026-08-213 min read

How to Add Subtitles to a YouTube Video (Without Uploading It to the Cloud)

Most subtitle tools require you to upload your video to a server. SublyAI works differently: the video stays in your browser, only the audio is sent for transcription, and burned-in subtitles are rendered client-side.

Step 1 — Download the YouTube video yourself

SublyAI does not fetch YouTube videos for you. Download the video first, then open it in SublyAI — nothing leaves your machine during upload.

SCREENSHOT PLACEHOLDER — PLACEHOLDER: add screenshot of the studio with a loaded video
Studio with a loaded YouTube video

Step 2 — Generate, or burn your own subtitles (free)

Generate subtitles automatically, or upload your own SRT/VTT and burn it in for free — no AI minutes deducted.

Step 3 — Fix sync with the trim tool

If your video starts with a different delay than the subtitles, use the trim tool to align the beginning. Trimming before generation also saves minutes.

VIDEO PLACEHOLDER — PLACEHOLDER: add screen-recording demo of the full flow
Demo: subtitling a YouTube video end-to-end