MR. BLINDBANDIT / CREATOR TOOLS

Chapter Markers

Add titled chapters on the playhead and export WebVTT or JSON.

Ready to choose a file. Engine loads on demand.

Technical details

Browser-local FFmpeg WebAssembly worker, Canvas and Web Audio. Single-worker fallback does not require SharedArrayBuffer. Files are not retained after reload.

How to use this tool

Choose your source file using the labeled file button.
Review metadata, preview and the relevant destination settings.
Start processing and keep this page open.
Download or share your finished file from the completion dialog.

Supported files and device limits

Common audio inputs include MP3, WAV, FLAC, M4A/AAC, OGG and Opus when the bundled engine can decode the codec. Images: JPEG, PNG and WebP. Convert HEIC to JPEG first. Large sources, long podcasts and 4K exports can exceed browser memory. Try a shorter clip or lower resolution if an export fails.

Privacy and troubleshooting

Source media stays in this browser session. The engine downloads from jsDelivr on first use; the provider receives ordinary connection information but no source media from these tools. Only non-sensitive destination preferences are saved locally. Retry after an engine error, close memory-heavy tabs or try a different browser. No higher-resolution setting can restore detail absent from your source.

Accessibility

Controls have text labels, timelines use numeric time fields, and downloads open in a keyboard-accessible dialog. Accessibility information and issue reporting.

Why chapters help listeners

Chapters split long audio — mixes, podcasts, interviews or audiobooks — into titled sections. Exported WebVTT chapter files can be used with web players, and JSON is handy for your own tools.

Step by step

Choose a file and play or seek to the start of a section.
Add a chapter with a short, descriptive title.
Repeat for each section.
Export as WebVTT or JSON.

Tips

Chapters make long audio much easier to navigate for screen-reader users, who cannot skim a waveform.
Use titles that describe the content rather than just numbers.
Check the first chapter starts at 0:00.

Screen-reader tips: every control has a text label, and progress and completion messages are announced in a live region, so you can keep your focus where it is. Use the heading keys to jump between the file, settings and results sections. Your file is processed in this browser and is not uploaded to the server; it is gone when you reload the page. See all media tools and the media suite terms.