Adding Smart Subtitles to Your Videos with AI

Subtitles improve watch time and accessibility, but writing them by hand is slow. whispernight.com can transcribe your video's audio track and generate timed, styled subtitles automatically.

Why subtitles matter

Most viewers watch social video with the sound off. Burned-in or platform-native subtitles keep your message clear either way, and they make your content usable for viewers who are deaf or hard of hearing.

Generating subtitles in whispernight.com

Start from a generated video's audio track.
whispernight.com transcribes the speech and aligns each line to its timestamp.
Choose a caption style — clean, bold, or highlighted-keyword — and export.

Tips for cleaner captions

Keep lines short — two lines of roughly 40 characters read best on mobile.
Review auto-generated text for names, brands, and numbers, which are the most common transcription misses.
Match your caption font size to your target platform's safe area so text isn't cropped.

Common subtitle mistakes

Even with automated transcription, a few habits separate readable captions from distracting ones:

Leaving auto-generated text unreviewed. Automated transcription is a first draft, not a final one. A single misheard word in the first few seconds can cost you the viewer, so always skim the full transcript before exporting.
Timing captions too tightly to speech. If a line appears and disappears in under a second, most viewers can't finish reading it. Give short lines a little extra hang time rather than cutting them exactly at the end of the spoken phrase.
Overloading a single line. Cramming a full sentence onto one line forces small text or a cropped caption box. Break longer sentences across two lines at a natural clause boundary instead of an arbitrary character count.
Ignoring contrast. Light text over a light background (or the reverse) is unreadable on a phone screen in daylight. A subtle outline or background plate keeps captions legible across busy footage.
Using inconsistent styling across a series. If you're publishing multiple videos to the same audience, switching caption fonts or colors between uploads makes your channel feel less cohesive. Pick one caption style and reuse it.

Export and format considerations

Once your captions look right, how you export them matters as much as how you wrote them:

Burned-in vs. platform-native captions. Burned-in (hardcoded) subtitles are guaranteed to display exactly as designed on every platform, but they can't be turned off by the viewer. Platform-native caption files (like .srt or .vtt) let viewers toggle captions and can improve accessibility, but rendering can vary slightly between apps.
Match resolution and aspect ratio to the destination. A caption size tuned for a square 1:1 post will look oversized or cropped on a 9:16 vertical export. Re-check caption placement any time you change the output aspect ratio.
Leave margin for platform UI. Most social apps overlay their own interface — like buttons, usernames, or a progress bar — near the bottom and sides of a video. Keep captions inside a safe area away from those edges so nothing gets covered.
Export a clean version alongside your captioned one. Keeping an uncaptioned copy makes it easy to re-export with a different caption style later, or to repurpose the same clip for a platform where you want the captions off entirely.