Free Windows app that translates, transcribes and re-syncs .srt subtitles for your own media library with Gemini (open source)
I watch a lot of foreign films I own and kept hitting the same problems: no subtitle in my language, a subtitle that drifts out of sync, or no subtitle at all. So I built SRT AI Translator NG, a free, open-source Windows app that handles all three with Google Gemini.
What it does
Translate an `.srt` into another language. Every batch must come back with exactly the lines it was sent, so the timing never shifts, and an interrupted run can be continued.
Transcribe the speech in a video or audio file into a new timed `.srt`.
Align a subtitle that runs early, late or drifts, using another subtitle or the video itself as the reference (including 23.976 → 25 fps fixes).
* Pick subtitle tracks straight from a video file, and add TMDB context (title, cast) so names and genders come out right.
* Extra care for Hebrew & other gender based languages: gender-aware translation using a reference subtitle, plus right-to-left display fixes for different players.
Good to know
* Portable: unzip and run. FFmpeg is included, nothing else to install.
* Bring your own Gemini API key. The free tier works, and the app paces requests so you don't hit the limits.
* Your subtitle text goes only to the Gemini API under your own key. Keys stay on your PC and never appear in logs.
* It's a standalone desktop app, not a Plex/Jellyfin/Kodi plugin: open a file, save the result next to your video.
* I built it with the help of AI coding assistants, and tested it a lot on my own films.
Screenshots:
· [Translate]
· [Transcribe]
· [Align]
· [Free-tier protection]
GitHub: https://github.com/Akila3/SRT-AI-Translator-NG
Feedback and bug reports are very welcome!