ASS to JSON Subtitle Converter

Quickly convert Advanced SubStation Alpha subtitles to Structured JSON locally in your browser. Timelines and subtitle content are never uploaded.

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What happens when converting ASS to JSON?

Advanced SubStation Alpha content is parsed into a unified millisecond timeline before being exported as Structured JSON. Valid timing and subtitle text are preserved.

JSON output gives every subtitle start_ms, end_ms, and text fields for further programmatic processing.

Complex ASS / SSA style tags and positioning are removed while visible text and timing are converted.

Format overview

About ASS and JSON subtitle formats

Learn what each file format is, how it is structured, where it is commonly used, and what to consider during conversion.

Source file format

ASS · Advanced SubStation Alpha

ASS, or Advanced SubStation Alpha, is an enhanced successor to SSA. It can precisely control subtitle fonts, colors, positions, animation, and karaoke effects.

File structure: ASS files are organized into sections such as Script Info, V4+ Styles, and Events. Subtitle cues are usually stored as Dialogue lines that reference predefined styles.
Common uses: ASS is commonly used for anime subtitles, visual subtitle effects, complex typesetting, karaoke, and video workflows that require precise presentation control.
Conversion notes: ASS can express much more styling than SRT, LRC, or TXT. When converting to a simpler format, this tool preserves visible text and timing but not complex styling, positioning, or animation.

Target file format

JSON · Structured JSON

JSON, or JavaScript Object Notation, is a structured data-interchange format rather than one industry-standard subtitle specification. Explicit fields can represent timing, text, and extensible metadata.

File structure: This tool uses a JSON object containing a cues array. Each cue has start_ms, end_ms, and text fields representing the start time, end time, and subtitle text.
Common uses: JSON is useful for subtitle software development, API exchange, batch processing, data analysis, automation, and preserving structured subtitle data for later programmatic or AI processing.
Conversion notes: Subtitle JSON schemas vary between applications. This tool can read subtitle arrays and objects containing cues or subtitles arrays, and it exports a consistent cues structure.