Subtitle Studio

Your subtitles run two seconds behind the film and now and then turn a line of dialogue into an ad for a website. Five small browser tools at Subtitle Studio repair files like that, each at a separate address on jamack.net and linked from a shared menu.

Convert takes several files at once and returns them in another format, for example a Korean SMI file as SRT. A second tab reads text from caption screenshots and VobSub, the picture subtitles on old DVDs. Spell applies the house style of broadcasters and streaming services, with several rules written for Korean text. It drops full stops at line ends and deletes web addresses that crept into the dialogue.

In Dual, two languages merge into one file, with the translation on a second line in a colour you pick. SubSync plays a video with its subtitles and can stream both to a TV, with the timing shifted in steps of a tenth of a second. The fifth tool, Sound, writes subtitles from the speech in a video.

Convert and Spell send files to the maker's server, and the Spell page says they are deleted after seven days. The pages open in Korean, with a menu at the top for English and 13 other languages. Visitors with an ad blocker are asked to switch it off before they continue.