Customize Subtitles, Control by Control

One look for every line

The Style tab controls the whole video at once. Change the font and every subtitle changes with it. There is no way to make a single line bold, tilt one word into italics, or give one speaker a different colour from another. That's a deliberate trade: one shared style keeps the preview, the rendered video and every line consistent, and you never hunt for the one subtitle you forgot to restyle.

Two consequences are worth knowing before you start. If you import an SRT or VTT file containing italic or bold tags, those tags are dropped on import and the words take on the video-wide style. And if a line has to stand apart, such as a translated sign or a voice from off screen, mark it in the text itself with a dash, a name or brackets rather than with formatting.

Presets come first

The panel opens with eight presets: Classic, YouTube, Modern, Minimal, Creator, Social Media, Cinema and High Contrast. Clicking one overwrites every setting below it, position included, so choose the closest preset before fine-tuning, not after. As soon as you move a slider, the preset tile stops showing as selected because your style no longer matches it exactly; that's expected, and your tweaks stay. A preset click you regret is undone with Ctrl+Z or Cmd+Z like any other edit. Subtitle styles describes the footage each of the eight is built for.

Text: font, weight, size and shape

The Text section holds the controls that change the letters themselves.

Font

A menu of 19 fonts grouped as Sans, Serif and Display. Characters a font doesn't cover, such as Devanagari or Arabic in a Latin-only face, fall back to a matching Noto font automatically.

Weight

Lists only the weights the chosen font really has. Bebas Neue, Anton, Bangers and Archivo Black come in a single weight, while Montserrat, Roboto, Lato, Merriweather and Cairo reach 900. Switching fonts moves you to the nearest weight on offer.

Size

A number from 1.5 to 16, measured against the video's shorter side. The default of 5.2 sets the font at roughly 56 pixels on a 1080p frame, and the same number scales up in proportion on a 4K file.

Italic and UPPERCASE

Two checkboxes. Italic looks right on fonts with a true italic; the display faces, Mukta and Cairo have none. UPPERCASE changes how the text is drawn, not what you typed, so an exported SRT keeps normal capitalisation.

Alignment

Left, Center or Right. Left- and right-aligned lines begin at the side margins of the safe area rather than at the frame edge.

Letter spacing

From slightly tighter than normal to wide tracking, set as a share of the font size.

Line height

The distance between the lines of a two- or three-line subtitle, from 0.90 to 2.20 times the font size.

Max line width

How much of the space between the side margins a line may fill before it wraps, from 30 to 100 per cent. Lower it for shorter, more compact lines.

Wrapping is automatic and aims to make two lines roughly equal in length instead of leaving one word stranded underneath. A line break you type yourself is always kept.

Colours, each with its own opacity

Every colour control has three parts: a swatch that opens your system's colour picker, a box for a hex code (short forms such as #ff0 are accepted), and an opacity slider running from 0 to 100. Which pickers you see depends on the background type.

• Text is always shown.
• Outline and Shadow appear for every type except None.
• Background appears only for Box and Rounded.

Opacity often does more than a new colour. A black box at about three-quarters opacity lets the picture show through while white text stays crisp, and a shadow at full strength looks far heavier than one at half. For combinations that survive both bright and dark footage, see readable subtitle colours.

Background: the edge around the letters

Five buttons set the treatment: None, Outline, Shadow, Box and Rounded. None draws bare text with no outline and no shadow, which only works over dark, even footage. The other four overlap more than their names suggest. Picking one switches that effect on with sensible defaults if it was at zero, but doesn't switch the others off, which is how the Cinema preset pairs a soft shadow with a hairline outline. To strip the outline from a boxed style, set its width to zero.

Advanced appearance opens the fine controls. All of them are relative to the font size, so they scale with the video:

• Outline width.
• Shadow blur, plus horizontal and vertical offset, so a shadow can fall down and to the right like cast light or sit directly beneath the letters.
• Padding X and Padding Y, for Box and Rounded, setting the room between the text and the edge of the box.
• Corner radius, for Rounded. Turn it right up and each line becomes a pill.

Each line of a multi-line subtitle gets its own box, sized to its own text, rather than one big rectangle. The shadow comes from the first layer painted: the box when there is one, otherwise the outline, otherwise the letters. Outline, shadow or box helps you decide between them.

Position and the safe area

The Position section offers Top, Middle and Bottom, plus a "Nudge up / down" slider for fine placement. Tick "Show safe area" to see the margins for your video's shape drawn over the preview. Placement is a topic of its own: moving subtitles to the top deals with anchors and nudges, and the subtitle safe area lists the margins for each aspect ratio.

Original subtitles

The final section isn't about your subtitles' appearance. "Hide subtitles already in the video" lays a blurred band across the frame, with sliders for its position and height, so old burned-in text beneath it can't be read and your new lines sit on top. It blurs that strip of picture; it doesn't erase anything. Hiding burned-in subtitles explains how to size it.

Customizing subtitles from top to bottom

1. Open the editor, choose your video and bring in some subtitles: AI, an imported SRT or VTT file, or a few typed lines.
2. Scrub to the shot where text will be hardest to read, usually the brightest or busiest one, and pause there.
3. Open the Style tab and click through the presets. Keep whichever is closest to what you want.
4. Set the font and weight, then the size. Judge size at the scale people will actually watch, not on a large monitor.
5. Choose a background type, then adjust colours and opacity until the text holds up on that difficult shot.
6. Open Advanced appearance only if the outline, shadow or box needs finer work.
7. Choose a position, tick Show safe area and confirm the longest line fits inside the guide.
8. Play the video through once before clicking Render video.

The preview runs the same layout code as the renderer, so the look you settle on here is the look the MP4 shows.

What can't be customized here

• Presets of your own. There's no save-style button. The style is kept with each video's draft in this browser, and it carries over when you open another video with Change video during the same visit, unless that video has a draft of its own, but it never becomes a named preset.
• Your own font files. The 19 bundled fonts are the full choice.
• Styling per line or per word, including speaker colours and highlighted words. Lines appear and disappear whole, with no motion.
• Styling inside subtitle files. Exported SRT and VTT hold text and timing only; the look lives in the rendered video.

If you need those, a desktop editor such as DaVinci Resolve gives each caption its own settings; adding subtitles in DaVinci Resolve walks through it. For type choices in more depth, fonts for subtitles compares all nineteen. No subtitles yet? The AI subtitle generator makes a timed file to start from.

About the subtitle editor on this page

Opens

MP4, MOV, M4V, WebM, MKV videos your browser can decode

Subtitles from

AI (from the speech, optionally translated into one of 21 languages), an SRT or VTT file, or typing them in

You download

An MP4 with the subtitles drawn into the picture at the original resolution and frame rate, plus SRT and VTT files

Cost

Editing, styling, rendering and SRT/VTT export are free, with no account and no watermark. AI subtitles cost 1 credit per minute (5-credit minimum per video); signing in with Google gives 100 free credits and accounts get 10 free credits a day

Privacy

The video never leaves your device and is rendered in your browser. Only for AI subtitles is the audio sent, over HTTPS, and it is deleted within 30 minutes of delivery

Rendering needs

Chrome or Edge 94+, Safari 16.4+, or Firefox 130+ on a computer. Editing and SRT/VTT export work in any current browser