Start from your local video
Use the same source edit that you published or plan to publish. Select an MP4 or WebM in Generate Subtitles and choose the spoken language. This site does not download YouTube URLs or connect to your channel. If the source exceeds 200 MB or 20 minutes, prepare a shorter edit outside the tool; captions generated for an excerpt will need a time offset before use with the full video.
Review text and timing first
Play the beginning, middle, and end of the video with the generated captions. Check names, line breaks, and when each caption appears. Download SRT after editing. If you later cut the video or add an intro, regenerate or realign the captions to the final edit instead of uploading a file with the old timing.
Upload a timed caption file
In YouTube Studio, open Subtitles, select your video, and choose the caption language. Use the file upload option and select the option for a file with timing. Upload the SRT, review its preview, then save or publish when ready. Check the official guide below if the interface labels change.
Check the viewer experience
Open the video player and check that the caption track can be selected and lines appear at the right moments. A selectable caption track is separate from the video image. This workflow does not burn captions into a new video or create a translated voice track. Keep the reviewed SRT so you can make later corrections.
Example
Final video edit → local caption review → SRT download → YouTube Studio caption upload → player check