Start here if…
These are troubleshooting references, not tutorials. Each one assumes you already have a file and something is wrong with it. Read the one that matches your symptom.
…you do not know which format to use
Subtitle formats compared covers what SRT, WebVTT, ASS/SSA, TTML, SBV and the rest actually are, which platforms accept which, and what you lose in each conversion. Read this before converting anything — it is cheaper than converting twice.
…the subtitles are out of sync
Fixing out-of-sync subtitles separates constant offset from progressive drift and tells you which tool fixes which. Getting this wrong is the most common way people waste an hour: shifting a drifting file moves the whole timeline when the problem is the frame rate.
…the subtitles will not display at all
Why subtitles are not showing is a seven-cause checklist — wrong container, missing track flag, burned-in assumptions, player settings, encoding, path issues and timing that falls outside the video. Work down the list rather than guessing.
…you need to check reading speed or compliance
Subtitle reading speed explains characters per second, minimum and maximum cue duration, line limits, and where the widely-cited thresholds come from — including which ones are platform requirements and which are just convention.
…you are embedding captions in a web page
Adding subtitles to HTML5 video covers the <track> element, the WebVTT requirement, CORS, and the accessibility reasons to use real captions rather than a styled overlay.
…you are sending subtitles out for translation
Translating subtitles covers the CSV round trip, why line breaks and cue counts must be preserved, and the three checks to run before delivering. Machine translation of a full subtitle file rarely produces something you can ship without this workflow.
How the guides relate to the tools
The guides explain diagnosis; the tools do the work. Most pages here link to the specific tool they are describing, so you can read the reasoning and apply the fix in one pass. Where a transformation is lossy or irreversible, the guide says so explicitly rather than leaving you to discover it after the fact.
What is not covered here
There is no guide on creating subtitles from scratch, because that is a transcription problem rather than a file problem — it needs audio, not a converter. There is also nothing on styling or karaoke effects: those live in ASS/SSA authoring tools, and the approach changes with every release of every editor, so a written guide would go stale faster than it would help.
What is covered is everything that goes wrong after a file exists and before it ships: wrong format, wrong timing, broken text, unreadable speed, missing captions on the web, and the handoff to a translator. Those six failure modes account for most of the support questions this kind of tooling attracts, and each one has a page.
Corrections
If something here is wrong, or a platform requirement has changed, tell us through the contact page. Subtitle specifications move — container support, caption styling rules and platform limits are all subject to change, and a guide that quietly goes stale is worse than no guide.
Last updated 2026-09-21.