Subtitle Edit

Subtitle Edit is a long-running open-source subtitle editor that has stayed actively maintained and added meaningful features each year. In 2026 it supports more than 300 subtitle formats, including the obscure broadcast standards that often block other tools, and ships with built-in Whisper integration for offline speech-to-text.

That means you can take a raw video file, run Whisper locally for a transcript, and edit timing and styling in the same application without round-tripping through a cloud service. For studios sensitive to privacy or working under NDA, that is meaningful.

The 5.0 beta line (Beta 24 as of May 2026) finally delivers a proper Avalonia-based macOS build with native Apple Silicon and Intel binaries — historically Mac was a real weak point, requiring a VM or the limited web port. The stable 4.0.15 release remains Windows-first.

Editor features include spell check, reading-speed indicators, line-break enforcement, format conversion, and translation via external services. The UI is dense and visually old-fashioned, especially next to a polished web tool, but the depth of capability is genuine.

Whisper integration depends on local compute power — long episodes take real time on modest hardware; the small model needs about 2 GB RAM, large benefits from 8 GB and a multi-core CPU. Free under permissive license.