Can I add captions on my phone?
Yes. The rules are the same. The risk is small type that looked fine in the editor and fails in the feed. Preview it as a viewer, not as the person who wrote it.
Reels
How to add captions to reels
Short answer: Put one idea on screen at a time, in type large enough to read on a phone, timed so the line is finished before the cut. The first line should be the point, not a greeting. This works in any editor. You do not need a new tool if the clip is already cut and you know the sentence.
If the clip is already the right length, you are not looking for a new edit. You are looking for words that a person can read before they scroll.
If you already have the short clip
Watch the clip once with sound and once without. Write the sentence you want a stranger to repeat. Then cut that sentence until it fits the runtime. A four-second clip cannot carry a three-line manifesto. Either shorten the sentence or use a longer clip.
Decide whether these words are a marketing line or a transcript. A marketing line is one claim. A transcript is every word, for access. Mixing them produces a paragraph in a bold font. If you need both, put the claim in large type and the transcript in the platform's caption field, or as real subtitles on a longer cut.
Timing: one idea per frame
Bring the line in when the proof appears, not three seconds after. If you say the number and then show the screen, the number should be up while the screen is up. Holding a line for the whole clip is fine when the clip is short. Swapping three lines in two seconds is not fine. People do not read at the speed of a cut.
Leave the line up long enough to read twice. A useful test: hand the phone to someone who has not seen the video and ask them to say the line back. If they miss the second half, you have two lines fighting, or the type is late.
01
Write the full sentence on paper
If you start in the editor, you will shrink the font to fit a bad sentence.02
Cut it to one breath
Read it aloud once. If you need a second breath, it is two captions or one shorter caption.03
Place it on the proof
The words and the picture should be about the same fact at the same time.04
Hold it
Do not animate it away before a person can finish reading.
The hook is the first line
The first words are the only words some people see. Do not spend them on 'So,' 'Okay so,' or the name of your company unless the name is the news. Start with the change, the number, or the objection. The logo can live in a corner. It should not be the sentence.
A hook that only works with the audio is not a caption. 'You will not believe the ending' over a normal demo teaches the viewer that your text is empty. They will believe that next time too.
Clip: 6 seconds of the import finishing. Weak first line "Let me show you something cool inside the product." Hook "Import finished. Invoice went out." The second version is the plot. The first version asks for patience a feed will not give.
Type, bars, and the buttons
Use a heavy weight. Put a bar or a stroke behind it if the background moves. White on white is the most common way a careful sentence becomes invisible. Check the export, not the preview on a calibrated monitor.
Keep clear of the UI. On Instagram and TikTok the right edge is buttons and the bottom is the username and the caption. A line that sits in either place will be covered. Center-left or true center, in the middle band of the frame, is the safe habit. Platform layouts move. Recheck when they do.
A caption that can convert
Conversion here means the viewer understands the offer well enough to watch the next second or open the profile. It does not mean a 'link in bio' sticker on a vague clip. The line should name the job the product did in the clip. 'Saved the Friday close' is closer to a conversion than 'We're so excited.'
If you have a number, use the number you can defend. Round numbers that were never measured get repeated in sales calls later, and then you have to walk them back. A smaller true number outperforms a larger invented one, because the rest of the reel has to live next to it.
- One claim.
- Words you would say on a call.
- A picture that matches the claim.
- Type you can read on a phone in daylight.
- No promise that was not in the footage or on the site.
Where Runmeg fits
If the clip is already cut and you only want the type styled, a caption product is enough, and Submagic is the name people compare for that narrower job. Runmeg is the wider job: a video you upload becomes captioned reels, and the line comes from the same voice as the posts. You still download and post. It will not place every word by hand the way an editor will. For that, stay in the editor you already have open.
Questions
Should captions be burned in or added by the app?
Burn the marketing line in if you want it to survive a repost or a download. Use the app's caption field for the longer note, hashtags, and context. Do not rely on the app field for the only sentence that matters.
How many lines is too many?
Two short lines is usually the ceiling for a reel. A third line means you are writing a post on top of a video. Move it under the video.
What font should I use?
A heavy sans you can read at arm's length. The font is not the strategy. If you are choosing between two fonts for an hour, the sentence is probably still too long.