Aegisub

Post-production subtitle work with precise timing and ASS karaoke styling

Aegisub is the canonical open-source subtitle editor and still the right tool for ASS work — karaoke timing, fansub-grade styling, frame-accurate adjustments. The official repo woke up again in 2026 after years of slow activity, with portable 3.4.2 builds and dark mode fixes shipping. UI is dense and the learning curve is real, but for serious ASS work nothing else gets close.

Aegisub is the open-source standard for serious subtitle editing, with origins in the anime fansubbing community and a still-loyal following in any post-production work that uses ASS subtitle format. The editor offers precise timing controls, frame-accurate alignment, audio waveform visualization, real-time video preview, and styling controls that go well beyond what cloud editors expose. Karaoke timing in particular remains uniquely well-supported, with letter-level effects and transitions accessible through the timing tool. Aegisub does not include speech recognition — you bring a transcript or SRT and edit timing and styling against the video. For workflows that already produce a transcript via Whisper or a hosted service, dropping the result into Aegisub for polish is still a sensible final step. After several quiet years where most progress lived on the arch1t3cht fork, the official repository started moving again — portable 3.4.2 shipped in January 2026 with dark mode fixes, and the fork is being migrated back into the main project. The UI is dense, with many panels active at once, and there is a real learning curve. Mac builds lag the Windows experience. For broadcast and accessibility work, Aegisub remains free, capable, and trustworthy — and the renewed activity in 2026 is the first real sign in years that the project has a future on the main repo rather than a fork.