Subtitles in AIX Player: load, style, sync and cast

AIX Player opens the subtitles inside a video and the subtitle files beside it, lets you make them readable, fixes their timing and shows the one you choose on the TV when you cast. Subtitle tools are free except the second subtitle track (AIX Pro); casting also has a free allowance.

Get AIX free from Microsoft Store

Windows 11 & 10 · AIX Player 3.0.16.0 · Reviewed 28 October 2026

Which subtitles it opens

Two kinds: the subtitle tracks inside a video, and subtitle files kept beside it.

• Tracks inside the file. Text and picture-based subtitle tracks in MKV, MP4 and the other formats AIX Player opens.
• Subtitle files. SRT, ASS, SSA, VTT, SUB/IDX, SUP, SMI, AQT, JSS, RT, SCC, TTXT, UTF and MKS.
• Picture-based subtitles. PGS from Blu-ray rips, VobSub from DVDs and DVB from TV recordings all decode, and so do closed captions. Teletext subtitles are not supported.

A subtitle file with the same name as the video loads by itself. Any other file loads from the subtitle menu, from any folder, with no renaming. Text subtitle files are read as UTF-8, or as UTF-16 with a byte-order mark; a file saved in an older regional encoding can show the wrong characters, and saving it again as UTF-8 fixes that.

Turn them on, off or change the language

Open the subtitle menu during playback to choose a track or switch subtitles off, or press J or V to step through the tracks. In Settings → Subtitle you can set a preferred subtitle language, which is chosen whenever a file offers it, and whether captions are on by default. If the first track is the wrong language, or only captions a few lines of foreign dialogue, pick the full track for your language: wrong-language subtitles explained.

Make them readable

Settings → Subtitle holds every control for how the text looks:

• Text size, for the distance you sit from the screen.
• Caption colour, including high-luminance colours that stay legible from across the room.
• Outline, a dark edge around each letter, and drop shadow, a soft shadow beneath the text.
• Background box, a solid panel behind the text for the brightest scenes.
• Bold, a heavier weight that helps thin type on a 4K screen.
• Vertical position, how high the lines sit from the bottom, for when they cover on-screen text.

Style override is on by default, so your settings also replace the styling an ASS or SSA file brings with it. Switch it off when you would rather keep the file’s own fonts, colours and positions. The style controls apply to text subtitles; picture-based tracks such as PGS keep the look they were made with. The subtitle styling guide covers which settings help most.

Fix the timing

If the words arrive before the lips move, or after, shift the subtitle delay earlier or later while the film keeps playing. Sound has its own audio delay for when the soundtrack is what drifted.

Scripts beyond the Latin alphabet

AIX Player bundles Noto Sans fonts for Arabic, Hebrew, Devanagari, Thai and Simplified Chinese, so subtitles in those scripts display without installing a font first.

Two languages at once

A second subtitle track (AIX Pro) shows another track at the same time, for example the language you are learning above your own, each with its own timing. It is for watching on your PC; a TV shows one subtitle during a cast. Set up dual subtitles.

Subtitles on the TV

When you cast, the subtitle you choose in AIX Player shows on the TV, whether it is a track inside the file or a separate file from your PC. Choose it before casting; some tracks can switch during a cast, while others need the preferred language set and a new cast. Settings → Casting has its own preferred subtitle language, selected when a cast begins. How the text looks on the TV can differ from your PC, so judge the size from where you sit. More on subtitles when casting.

Casting is part of AIX Pro: the free app includes 60 casting minutes in total, once, not per session, and Pro makes casting unlimited. Playing supported SDR files on your PC is free with no time limit.

Free and Pro

Every subtitle format above, track switching, styling, timing and the bundled fonts are free. The second subtitle track is part of AIX Pro.

Subtitle guides

• How to add an external subtitle file
• Subtitles not showing on an MKV? What to check
• Fix subtitles that are out of sync
• Make subtitles easier to read
• SRT, ASS, VTT and PGS explained
• Two subtitle tracks at once for language learning
• Why subtitles vanish when casting, and the fix