Adding captions for Instagram Reels, TikTok and YouTube Shorts
Updated
Social feeds need captions burned into the picture, because they accept a video file and no separate subtitle file. Keep them above the bottom fifth of the frame, where the platform's own interface sits, use a heavy font with a thick outline so they read over any footage, and keep lines to roughly 20 characters on a vertical clip.
Why burned-in, and not the platform's own captions
All three platforms will generate captions for you, and there are two good reasons not to rely on them. The first is control: you do not choose the wording, the styling, or the position, and you cannot fix a mistranscription of a name or a product.
The second is that they are not guaranteed to be showing. Auto-captions can be toggled off by the viewer, are not always generated, and behave differently when your video is reposted or downloaded. Burned-in captions are part of the picture, so they survive every one of those paths.
Position them above the interface
The bottom of a vertical frame is not yours. The handle, the description, the audio credit and the buttons all live there, and a caption placed at the very bottom — where a subtitle would normally go — ends up behind them.
Keeping captions above roughly the bottom fifth of the frame clears that furniture on all three platforms. The Social bold preset here is positioned for exactly this, which is why it sits noticeably higher than the standard subtitle preset.
Make them legible over anything
A social clip cuts between a bright sky and a dark interior in the space of a second, and white text with no outline disappears over the first of those. An outline — a thick one, around fourteen per cent of the font size — is what makes captions readable over unpredictable footage, and it is the single biggest difference between captions that work everywhere and captions that vanish.
Heavy weights and uppercase read faster at a glance, which is what a muted autoplaying feed asks for. On a longer, more considered piece, sentence case and a lighter weight are easier to read for minutes at a time — which is the tradeoff between the Social bold and Clean subtitle presets.
Export settings that survive the upload
Every platform re-encodes what you send, so the file you upload is not the file viewers watch. What you can control is giving their encoder something clean to work from: H.264 in MP4, at the resolution you shot, with a generous bitrate.
That also means captions should be crisp and high-contrast when they leave you. Thin text and subtle colours are the first things a platform's compression destroys.