Subtitle Tools

Aegisub

Aegisub is a subtitle editor for timing, styling, and typesetting captions against video. It combines a waveform or spectrum audio view, a live video preview, karaoke tooling, and Lua automation for effects that would be tedious by hand.

Visit official website ↗
✓ Software download·Open Source·Updated October 9, 2026
DeveloperAegisub Team
LicenseOpen Source
File size46.9 MB
LanguageNotes File MD5
Downloads374

Aegisub: Subtitle Timing, Typesetting, and Karaoke Effects

Aegisub is a subtitle editor built for people who need precise control over when a line appears and how it looks. The window pairs three views: a subtitle grid listing every line, an edit box for text and formatting, and an audio display that can switch between waveform and spectrum so dialogue and effects are easy to see. Timing is done by listening and pressing keys to set start and end points, with the video pane showing the frame where each line lands. Styling uses the ASS format, so fonts, colours, positioning, and effects are stored in the script itself.

What separates Aegisub from simpler caption tools is the toolset around the editor. The video pane is interactive: you can drag, rotate, and crop a subtitle to sit exactly on an onscreen sign, then reuse that positioning as a style. A spell checker reviews dialogue, the translation assistant speeds up working from a finished script in another language, and the kanji timer handles per-character timing for Japanese songs. Style and line changes are handled by dedicated managers rather than manual editing, and the automation manager runs Lua scripts, including the karaoke templater. Preview rendering uses the same subtitle engine as many players. For playback of the finished file, LAV Filters is a common companion.

Benefits of Using Aegisub

Speed is the main argument for Aegisub. Timing a 24-minute episode by hand is bearable when the workflow is a waveform, a keyboard, and immediate feedback, and much of the tooling is designed to remove repetition: shift times nudges an entire script, the timing post-processor repairs overlapping lines, and duplicate checks catch near-identical entries. The interactive video pane means typesetting signs does not require guessing coordinates in a text editor, and the finished look can be verified frame by frame. Whole categories of subtitle work become practical, from karaoke effects driven by Lua templates to restyling a release for a different resolution with one tool. Because everything lives in an open script format with styles, attachments, and automation, an Aegisub project can be handed to a collaborator, re-timed, and rebuilt without starting over.

Aegisub features

Key capabilities and highlights.

Feature 1

Waveform and spectrum timing

The audio display renders a loaded track as either a waveform or a colour spectrum, and you set line start and end points with keys while playback continues. Snapping markers to nearby peaks and zooming into quiet passages makes dialogue and sound effects easy to time accurately.

Feature 2

Interactive video typesetting

The video pane shows subtitles rendered exactly as they will appear, and the visual tools let you drag, rotate, clip, and scale lines with the mouse until they sit on an onscreen sign. Those adjustments are written back as positioning tags, so typesetting stays reproducible.

Feature 3

Style and attachment management

Styles store font, colour, size, outline, shadow, and positioning settings so a whole script can be restyled from one place. The fonts collector gathers every font referenced by the script into a folder, and the attachment manager embeds them, which matters when a release has to look identical on other machines.

Feature 4

Automation and Lua scripting

Aegisub exposes its internals to Lua through the automation manager, so repetitive jobs can be scripted instead of clicked through. Bundled scripts include the karaoke templater, which turns styled template lines into timed per-syllable effects, along with utilities for tags, positioning, and batch edits.

Feature 5

Translation and kanji tools

The translation assistant walks through a script line by line so a translator can see the original while typing the new text, and the kanji timer splits a line into individual characters for precise timing. Both are aimed at imported scripts where the words exist but the timing and language still need work.

Feature 6

Timing repair and shift times

Shift times moves every line in a script by a fixed offset, while the timing post-processor adds sensible lead-in and lead-out durations and flags lines that overlap or run too short. Together they clean up a rough first pass without adjusting hundreds of entries individually.

Feature 7

Select lines and find and replace

Lines can be filtered with rules covering style, actor, text, timing, and duration, which is how a large script gets narrowed down to the entries that need attention. Search and replace supports regular expressions, so patterns such as stray tags or inconsistent punctuation can be corrected across the file in one action.

Feature 8

Format conversion and spell check

Aegisub imports and exports the common subtitle formats as well as the rich ASS script it is designed around, so a finished project can be delivered as a plain caption file when required. A built-in spell checker reviews dialogue in the edit box and jumps between mistakes.

Old versions

Browse historical releases and previous builds.

3.4.2January 13, 2025
3.4.1January 1, 2025
3.4.0December 19, 2024
3.2.2December 8, 2014

Frequently asked questions

Common questions about Aegisub.

What is Aegisub best at?

Timing and typesetting. The audio display makes setting line boundaries fast, the video pane removes guesswork when placing text over signs, and the style and automation systems mean the result can be reused rather than rebuilt. It is aimed at people producing subtitles professionally or for fan projects.

Do I need the video file to use Aegisub?

No. Timing can be done from audio alone, which is common when working from a soundtrack or a script that arrives before the footage. Loading video is what unlocks visual typesetting and frame-accurate checks, so it becomes necessary once you start positioning text rather than just captioning dialogue.

What file format does it work in?

Aegisub is built around the ASS subtitle format, which stores styles, positioning, and effects inside the script, and it reads the older SSA variant as well. Finished work can be exported to plain caption formats for players and platforms that do not support the richer styling.

Can I automate repetitive subtitle work in Aegisub?

Yes. The automation manager runs scripts written in Lua, and the bundled set already covers common jobs such as applying karaoke templates, adjusting tags, and processing selected lines. You can write your own scripts against the same API, which is why teams with unusual workflows rarely do everything by hand.

How does Aegisub keep its preview accurate?

The preview is rendered by the same subtitle library that many players and encoders use, so fonts, outlines, shadows, and positioning appear the way they will on screen rather than as a rough approximation. A styling assistant and colour picker make it easier to adjust the result while watching it.

Is Aegisub suitable for karaoke subtitles?

Yes. Karaoke work is one of its strongest areas. Lines are timed per syllable, and the karaoke templater converts styled template lines into effects automatically, including highlighting that follows the singing. That makes a full song practical to produce instead of a weekend of manual tag editing.

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Software download

Download Aegisub

Aegisub is a subtitle editor for timing, styling, and typesetting captions against video. It combines a waveform or spectrum audio view, a live video preview, karaoke tooling, and Lua automation for effects that would be tedious by hand.