Subtitlesync Pro

SubtitleSync Pro — Universal Subtitle Overlay for Any Video
SubtitleSync Pro adds subtitle support to any HTML5 video on the web. Upload your own subtitle file and it overlays directly on the video player — no account, no sign-up, no server required. Everything runs locally in your browser.
How it works
Open any page with a video, click the extension icon, upload a subtitle file, and press Apply. Subtitles appear on the video immediately and stay in sync with playback.
Features
🌐 Universal compatibility — works with HTML5 video players across most websites including YouTube, Vimeo, and custom media players
📄 Multiple formats — supports SRT, VTT, ASS, and SSA subtitle files
⏱️ Real-time sync adjustment — shift subtitle timing forward or backward in 0.5-second steps to correct any timing mismatch without editing the file
🎨 Fully customizable appearance — adjust font size, text color, and vertical position to match your preference
🔍 Built-in subtitle search — search OpenSubtitles directly from the popup and download subtitles in one click, or use Podnapisi and Google as alternative sources
💾 Session persistence — subtitles are automatically restored when you reload the page, so you never lose your place
🖥️ Fullscreen support — subtitles remain correctly positioned when entering or exiting the browser's native fullscreen mode
🔒 Fully private — no data is sent to any server. Your subtitle files and viewing activity never leave your device.

Compatible with Chrome and Chromium-based browsers. Works on most sites that use an HTML5 video element.