Effective 2026-10-28. Linesub is provided by PRODUCTIVITY TOOLS LIMITED, Hong Kong ("we"). Using the app means you accept these terms.
The app adds subtitles to a video you choose, in the language you pick: the video's sound is written down and translated by AI providers (Groq and OpenAI), and your phone writes the subtitles into a copy of the video. AI subtitles can miss words, mishear names or mistranslate; check them before you rely on them.
Choose only videos you own or have permission to use. Do not use the app for unlawful content or content that violates other people's rights. You keep all rights to your videos and to the copies with subtitles. See the Privacy Policy for what is sent and how long it is kept.
Each phone gets two free minutes, once. Minute packs bought through Google Play or the App Store add the minutes shown on the purchase screen; they never expire. A video costs its length, counted to the second and rounded up, and bought minutes are used before the free ones. A video that fails on our side, finds no speech or is cancelled while it is processed costs nothing. If your phone cannot write the subtitles into the video, the minutes stay used and "Try again" writes them without another charge. Videos already made stay usable on your phone. Refunds follow the store's policy. Use "Restore purchases" after reinstalling or changing phones.
Videos up to 10 minutes are accepted. We may limit or block use that looks automated or abusive, including sound that keeps failing or videos cancelled again and again, and we may change limits or prices for future purchases.
If subtitles are offensive or wrong, use "Report" in the app or email us.
The service is provided as is. To the extent the law allows, our liability is limited to the amount you paid in the previous month. These terms are governed by the laws of Hong Kong.
Contact: support@productivitytools.app