The best fonts for captions and subtitles, and how big to set them
Which typefaces stay readable at caption size, what broadcasters actually specify, and how large captions should be on landscape and vertical video.
Updated 6 min readBy the AutoCap team
A caption font has a harder job than almost any other text. It appears for a second or two, over a moving picture, often on a small screen, and the viewer has to read it without looking away from the video. Plenty of good-looking fonts fail that test. The ones that pass have a few things in common, and the broadcasters who caption for a living have written down what they use.
What makes a caption font readable
- Sans serif. Serifs and thin strokes break up at small sizes and on compressed video. Every major captioning guide asks for a sans serif.
- Open, wide letter shapes. Generous counters (the holes in a, e and o) and a tall x-height keep letters distinct when they’re small or slightly blurred.
- Letters that can’t be confused. A capital I, a lower-case l and the number 1 should look different, and so should O and 0.
- Medium or bold weight. Light weights disappear against busy backgrounds; very heavy weights close up their counters at small sizes.
What the style guides specify
Three guides cover most professional captioning: the BBC Subtitle Guidelines (version 1.2.5, March 2026), Netflix’s timed text style guides, and the US DCMP Captioning Key. They agree more than they differ:
| Guide | Font | Look |
|---|---|---|
| BBC Subtitle Guidelines | Reith Sans, Arial or Roboto in the file; author in a wide font such as Reith Sans, Verdana or Tiresias | White text on a black background |
| Netflix | Arial, as a stand-in for a proportional sans serif | White, sized so 42 characters fit across the screen |
| DCMP Captioning Key | A medium-weight, proportionally spaced sans serif | White with a drop or rim shadow; a translucent box is preferred |
Fonts that work, by job
The right font depends on what the captions are for. Subtitles someone will read for twenty minutes need different qualities from three words that pop onto a TikTok.
- Long-form video, courses and interviews. Arial, Verdana, Roboto or Inter in a medium weight: plain, wide and easy to read line after line.
- Short social clips. A heavy display sans such as Montserrat in its bold weights, Anton, Archivo Black or Inter Tight, with an outline or shadow. Condensed faces like Anton fit more letters on a narrow vertical frame.
- One word of emphasis. Script, serif and decorative fonts can work for a single highlighted word or a title card. For running captions, they slow reading down.
AutoCap’s caption styles are built on these faces, and you can change any style’s font or upload your own on a paid plan.
How big captions should be
The BBC measures subtitle size as line height, a share of the video’s height. Its figures are the most specific any guide publishes:
- Landscape, 4:3 and square video: 7–8% of the frame’s height per line.
- Vertical 9:16 video: 3.9–4.5% of the frame’s height. On a 1920-pixel-tall frame that works out to lines about 75–86 pixels tall (our arithmetic, not the BBC’s).
- Line width: up to 68% of a 16:9 frame and 90% of a 4:3, square or vertical one, with at most two lines on landscape video and three on vertical.
Netflix takes a different route: subtitles are sized relative to the video so that 42 characters fit across the screen. None of TikTok, Instagram or YouTube publishes a minimum caption size for vertical video; Meta’s ad guidance only asks for a type size that’s large enough to read. Bold social styles usually run larger than the BBC’s figures, which works as long as each caption stays short.
Color, outline and box
All three guides start from white text. The BBC puts it on a black background, and DCMP prefers a translucent box or a drop shadow. For bold social styles, a solid dark outline does the same job: whatever the picture behind it does, the edge of every letter stays visible.
Colored text works best for a highlighted word or for telling speakers apart; the BBC keeps a small set of colors (white, yellow, cyan and green) for exactly that. More on timing, line length and placement is in caption best practices.
Fonts for other languages
A font is only as good as the letters it contains. Many display fonts cover English and little else, so a Hungarian ő, a Romanian ș or a Polish ł appears in a different typeface from the rest of the word, or as a substitute letter. Greek and Cyrillic need fonts that include those alphabets at all.
Before you settle on a font, preview a word that uses your language’s special letters in the actual caption style. The language pages list the letters each language needs a caption font to carry.
Questions
What is the best font for subtitles?
A clear sans serif with open letter shapes, set in a medium or bold weight. The BBC recommends wide fonts such as Reith Sans, Verdana or Tiresias, Netflix uses Arial as its stand-in, and Roboto is a widely available free choice.
What font is best for TikTok and Instagram captions?
A heavy sans serif such as Montserrat, Anton or Archivo Black, with a dark outline or shadow, stays readable over moving video on a phone. Save decorative and script fonts for a single emphasized word.
How tall should captions be on a 1080×1920 video?
The BBC’s guideline for vertical video, 3.9–4.5% of the frame’s height per line, works out to lines about 75–86 pixels tall on a 1920-pixel frame. Bold social styles often run larger; keep the lines short so they still fit.
Should captions be in all caps?
Mixed case is easier to read, and the DCMP Captioning Key prefers it. All-caps styles are common in short-form video; if you use one, keep each caption to a few words.
Can I use my own font in AutoCap?
Yes, on a paid plan. Upload the font file and any caption style can use it.