FOUR CAUSES, ONE LOOK AT THE SCREEN
Subtitles not showing on iPhone or CarPlay? What you see names the cause.
Subtitles not showing on iPhone or CarPlay has four usual causes, and what is on screen tells them apart. Nothing at all, with a track listed, means it is not selected. Boxes or question marks mean the file is not UTF-8. A blank disc rip means image-based PGS or VobSub. An empty menu means the sidecar never paired.
- 01
A listed subtitle track is idle until you select it in Audio & Subtitles.
- 02
Boxes and question marks are an encoding problem, not a player problem.
- 03
Caption size, font and background come from iOS Settings, not from the player.
How it works
Your quick start
- 01
Open Audio & Subtitles
Dashow’s options menu lists the subtitle tracks the video offers and the files that came in with it.
- 02
Select the listed track
A track sits idle until you choose it by name, so pick the language you want and let the picture run.
- 03
Match the symptom
Nothing at all, boxes and question marks, or an empty menu each point at a different cause.
- 04
Set the size in Settings
Subtitle size, font, colour, edge and background come from Settings → Accessibility → Subtitles & Captioning.
Subtitles not showing at all usually means nothing is selected.
Open the options menu in Dashow. Audio & Subtitles lists the video’s own text tracks and any subtitle file that came in with it, by name and language. A track that is listed is not a track that is drawing. Choose the one you want and the lines appear at its next cue.
This is the commonest case and the fastest to rule out. An MKV from a release group often carries three or four subtitle tracks, one per language, plus a forced track that covers only the non-English dialogue. They are separate tracks and you pick between them by name. Select it and watch one line of dialogue. What happens next is the rest of this page.
Boxes and question marks are the file’s encoding, not the player.
Look at one accented word. If it comes out as a box, a question mark or a run of nonsense, the subtitle file is stored in something other than UTF-8. SubRip carries no declaration of its own encoding, so an .srt saved in Windows-1252, Big5 or Shift_JIS hands the renderer bytes it reads as different characters.
The fix is on the file, not in the player. Open the .srt in a plain text editor and save it again with the encoding set to UTF-8, then play the video once more. WebVTT avoids the question entirely, because the specification requires every .vtt file to be UTF-8, which is why the same lines saved as .vtt come out clean when the .srt did not.
PGS and VobSub tracks are pictures of words.
A Blu-ray rip carries its subtitles as PGS, and a DVD rip as VobSub. Both store each line as a bitmap with a start and end time rather than as characters. Matroska puts both under track type 17, subtitle, and tells them apart by codec ID, so an .mkv can hold a subtitle track that no text renderer has anything to draw from.
Text is what a subtitle renderer draws. The route to subtitles on a disc rip is a text track: an .srt or .vtt of the same film, which Audio & Subtitles lists next to the file’s own tracks. The symptom names itself. You pick the track by name, nothing appears, and the file is a Blu-ray or DVD rip.
An empty menu means the sidecar file was never paired.
The fourth symptom is the opposite of the first. Audio & Subtitles lists the video’s own tracks and no sign of the .srt you put next to it, or lists nothing at all. On a share the file is found by its name, and a name that does not match the video’s closely enough is read as belonging to another file. Only .srt and .vtt are read.
The exact naming rule, the language tag and where the file goes on an SMB or WebDAV share belong to the guide on SRT subtitles on iPhone. Go there for a subtitle that has never once appeared. Come back here for a track that is listed and still shows nothing. An .ass or .sub file is a different format from the two that are read.
Subtitle size, font and background come from iOS Settings.
Subtitles that appear but sit too small, or in a colour that vanishes against a bright scene, are a styling question rather than a playback one. Imported subtitles follow the system caption style. Open Settings, then Accessibility, then Subtitles & Captioning, and tap Style. One of the ready-made styles or one you create sets the font, the size, the colour, the background and the text edge.
The setting belongs to iOS rather than to one player’s menu, so the style you build there is the style your imported subtitles arrive in. Set it once. A larger size with a solid background is the pairing that reads best on a car display, where the picture sits further from your eyes than a phone in your hand. Play the video again and the new style is in place.
Subtitles on only some lines are a forced track.
Subtitles that show on only some lines are a forced track doing its job. That track holds the lines a viewer needs without the rest of the dialogue, and Matroska sets FlagForced on it so a player can select it even when subtitles are otherwise off. Open Audio & Subtitles and pick the full-language row instead.
Two cases sit outside this page. A subtitle file that no menu has ever listed is about pairing rather than display, and the guide to SRT subtitles on iPhone carries the naming rule. If the video will not start, open Details, which reads duration, dimensions, codecs, file size and embedded title from the file, then see the guide to iPhone video formats and the one on playing MKV files.
