YouTube JSON3 to LRC Lyrics Converter
Transform YouTube timedtext JSON3 subtitles into synced LRC lyrics for LRC-capable music players.
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Supports .json, .json3, .xml, .html files up to 50 MB
About JSON to LRC
YouTube's timedtext API serves captions in JSON3 format — a JSON structure with an events array where each event carries a tStartMs timestamp and segs text fragments. This tool parses the JSON3 structure, extracts each event's start time and text, and outputs [MM:SS.xx] LRC lyrics usable in foobar2000, AIMP, Poweramp, and other players that support LRC time tags.
JSON to LRC Code Syntax & Structure Inspection
Side-by-side code inspection illustrating header definitions, timestamp syntax, and cue payload formatting
JSON vs LRC Technical Specifications
JSON
JSON3 is YouTube's internal subtitle format, exported via the timedtext API. The file is a JSON object with an events array. Each event has tStartMs (start millisecond), dDurationMs (duration in ms), and segs (an array of text fragments, each with a utf8 field). Users typically download this format using youtube-dl, yt-dlp, or similar tools.
LRC
LRC (.lrc) is a synchronized lyrics format that displays text line-by-line in music players. Each line begins with a [MM:SS.xx] time tag and does not store an end time — the player automatically advances to the next line.
Format Differences
Conversion Troubleshooting & Gotchas
Practical solutions for player compatibility, character encoding, and timing synchronization
Subtitle timing drifts or appears out of sync on media players
Video files frequently differ in framerate (e.g., 23.976 fps vs 25 fps). If the timing drifts steadily, use our Subtitle Sync tool to adjust the global offset or framerate stretch.
Characters appear as garbled symbols or question marks (Mojibake)
Legacy files saved in Windows-1252, Shift-JIS, or GBK may render incorrectly. Our exporter standardizes output to clean UTF-8. Use our Subtitle Encoding Converter if the source file is corrupted.
Overlapping captions when multiple speakers talk simultaneously
Different formats handle overlapping dialogue differently. If your target player cannot render stacked cues cleanly, open the file in our Subtitle Editor to adjust individual cue timings.
Video editing software (Premiere, DaVinci, Final Cut) rejects the file
Professional NLE software enforces strict syntax rules. Our converter eliminates malformed line breaks and non-standard tags, producing clean, standardized files.
Features
Why Convert?
Common Use Cases
YouTube Music Lyrics Extraction
YouTube auto-captions download as JSON3, but music players need LRC. Convert JSON3 to LRC to turn YouTube subtitles into synced lyrics for foobar2000, AIMP, and Poweramp.
yt-dlp Subtitle to Lyrics
YouTube subtitles downloaded with yt-dlp are typically JSON3 format. Convert JSON3 to LRC to reuse them as synced lyrics in LRC-capable audio players.
Language Learning Materials
JSON3 subtitles from YouTube educational videos can be converted to LRC for language learning apps that show synced text during audio playback.
Discord Bot Lyrics
Discord music bots use LRC format to display synced lyrics during playback. Convert YouTube JSON3 subtitles to LRC to integrate with your bot.
Mobile Music Players
Many mobile music players support LRC synced lyrics. Convert YouTube JSON3 subtitles to LRC for use in apps that accept LRC time tags.
Related Formats
LRC (Lyrics)
Output format — a synchronized lyrics format with [MM:SS.xx] timestamp tags, used by music players like foobar2000, AIMP, Poweramp, and MiniLyrics.
JSON (YouTube JSON3)
Input format — YouTube's timedtext API subtitle format with events array and segs text fragments. Convert JSON3 to LRC to reuse YouTube subtitles as lyrics.
SRT (SubRip)
Universal subtitle format. If you need video player subtitles instead of music player lyrics, convert JSON3 to SRT in the workspace.
How It Works
- 1
Upload or drag your .json file into the tool area.
- 2
The parser reads the JSON structure and iterates the events array.
- 3
Each event's tStartMs millisecond value is converted to LRC's centisecond [mm:ss.xx] timestamp.
- 4
The utf8 text fragments in the segs array are concatenated into a single LRC lyrics line.
- 5
Timing-only events without segs are automatically skipped.
- 6
The resulting .lrc file pairs each bracketed timestamp with a line of lyrics text.
More Subtitle Tools
Frequently Asked Questions
JSON3 is YouTube's internal subtitle format. It is served via the timedtext API as a JSON object with an events array. Each event has tStartMs (start millisecond), dDurationMs (duration in ms), and segs (text fragments array, each with a utf8 field).
The generated file uses common LRC [MM:SS.xx] time tags. With foobar2000 (ESLyric), AIMP, Poweramp, and similar players that support this syntax, name the lyrics file the same as the audio file to enable synchronized display.
Some events in YouTube JSON3 contain only timing information (like aAppend markers) without text fragments. These events are automatically skipped during conversion and do not affect the LRC output.
Use yt-dlp: yt-dlp --write-auto-sub --sub-format json3 <video-URL>. The downloaded .json3 file can be directly imported into this tool. You can also fetch it via the YouTube timedtext API in a browser.
The multiple utf8 text fragments in each event's segs array are automatically concatenated into a single LRC lyrics line, and internal line breaks are converted to spaces. For example, two fragments "Hello " and "world" are merged into "Hello world".
LRC is a lyrics file format that uses time tags to synchronize text with music playback. Each line starts with a [MM:SS.xx] timestamp.
Related Articles
Convert YouTube JSON3 Subtitles to SRT, VTT, or LRC | AllSubConverter
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