About Subtitle Editor Online
Subtitle Editor Online is a free, open-source, browser-based editor designed for video creators, filmmakers, translators, and educators.
Built for Privacy and Speed
Most web-based video tools require uploading your footage to remote servers, raising privacy concerns and wasting bandwidth. Subtitle Editor Online operates on a local-first architecture. All video decoding, waveform rendering, and subtitle cue synchronization occur directly in your browser memory via modern Web APIs.
Our AI Subtitle Generator leverages WebAssembly and WebGPU to run OpenAI's Whisper model locally on your hardware. Spoken audio is transcribed directly on your CPU/GPU, ensuring that unreleased videos, confidential recordings, and personal content never leave your computer.
100% In-Browser Privacy
Your media files remain on your device at all times. We do not upload your video files or subtitles to external cloud servers.
Zero Installation Friction
Works instantly on Windows, macOS, Linux, and Chromebooks. Open the website, drag in your video and subtitle files, and begin editing immediately.
Local AI Speech Recognition
Auto-generate time-coded SRT subtitles using Whisper AI running locally in your browser with no API keys or per-minute transcription fees.
Free & Open Source
Every feature — visual timeline synchronization, SRT & WebVTT import/export, and AI transcription — is free without paywalls or watermarks.
Open Web Technology Stack
Our platform relies on modern web standards to deliver smooth timeline scrubbing and accurate subtitle synchronization:
Ready to Edit Subtitles?
No registration or installation required. Launch our timeline editor or try the AI subtitle generator now.