# Merge multiple MP3 files into a single MP3 with chapters.

This simple online tool allows you to stitch together multiple MP3 files. It is open source, does not require install or signup, and runs locally in your browser. Your files are never uploaded. It adds `id3` chapter metadata that is supported by many podcast players.

To start, load your audio files.

or drag and drop files
Drop mp3 files to load.

Use filenames instead of file titles for chapter names
Use millisecond accuracy for chapter start times
Preserve chapters in input files in the merged file
Use cover images as chapter images
Re-encode audio (slow, but may be needed if input files are incompatible)
Merged MP3 File

### Edit chapters

Chapters are managed using the same syntax also used by YouTube. Each chapter is one line, starting with the timestamp when the chapter begins (for example `03:20` or using milliseconds `14:21.320`), followed by a space, followed by the name of the chapter. Chapters can also have a link and an image associated with them, see below for details.

Advanced: Chapter URLs, images, hidden chapters

Each chapter can be assigned a link that will be shown by some players. To add a link, add the URL (starting with `http://` or `https://`) to the end of the chapter line.

Each chapter can be assigned an image. To add an image, upload an image below and add its code (for example `<img-6>`) to the end of the chapter line. Images in the gallery that are not assigned to a chapter are ignored. The same image can be used for multiple chapters. Images larger than 1400px wide or tall will be scaled down. A chapter can get both a link and an image. You can also paste an image from the clipboard; if you do this while editing the chapter list, the correct image code will be inserted at the cursor position.

A chapter can be hidden from the table of contents (i.e., the chapter list). This can be useful to show a chapter image for some time period without showing a separate chapter. To hide a chapter, begin its name with `_` (an underscore), for example `_photo` or simply `_`. Note that hidden chapters are ignored by some players.

or drag and drop file or paste an image
Drop an image file to load.
Podlove Simple Chapters XML and Podcast Namespace JSON

Besides embedded ID3 chapters, other standards for specifying chapters exist. Examples are the Podlove Simple Chapters XML and Podcast Namespace Chapter JSON formats, which can be added to a podcast RSS feed via embedding into the `<item>` tag (XML) or by adding a link (JSON, XML). While most podcast players use embedded chapters, some other players (notably Spotify) only support time stamps in the episode description or Podlove chapters.

Include image links

You will need to upload the images to a web server and add the URLs to the chapter list.

Image base URL
Podlove Simple Chapters XML

Podcast Namespace JSON

### Edit MP3 tags

MP3 files can contain metadata such as title, artist, etc., known as ID3 tags. You can edit these tags below.

Title
Artist / Author
Album / Podcast name
Track number / Episode number
Year
Release Date (YYYY-MM-DD)
Genre
Copyright
Publisher
Language
Encoded by
Website
Cover image
Drop mp3 files to load.