Live demo

Try it: check webinar captions and page alt text

This is the working version of the caption and alt-text tutorial. It reads a caption file and the HTML of a page you open or paste, and flags cues that are too short, too long, too fast, over your line limit or overlapping, plus images with missing, empty, file-name or repeated alt text. It does not caption anything, write any description or judge whether either is right.

How this lab works

• Everything on the page runs in your browser. The kit's script runs the same checks from a command line and can read several files in one run, which the page cannot.
• It flags and does not fix. The download lists each flag with empty decision and reason columns for a person to fill in.
• The numbers are examples. Edit every limit. The length flag and the "image of" check are house checks with no cited source.
• It cannot judge words. It cannot tell whether a caption is accurate, a speaker is named correctly or a description is useful. The two prompts for a person only note that no speaker labels or sound notation were found.
• Reading speed is per cue. Each cue is compared with the limit on its own, which is a simplification.
• The samples are synthetic. They are one invented six-cue caption file and seven invented image tags, built to trigger flags.
• Local only. The script is served from this site and the page makes no other request for your files.

Starter kit

The starter kit holds this page to run on your own computer, the same checks as a script, the two sample files, a settings worksheet, a review checklist and a log for accepted flags. Free with your email through the form below; the download link appears after you subscribe.