Fission Icon


Fast & lossless audio editing

Crop and trim audio, paste in or join files, or just rapidly split one long file into many. Fission is streamlined for fast editing. Plus, it works without the quality loss caused by other editors, so you can get perfect quality audio even when editing MP3 and AAC files.

If you need to convert formats, Fission can do that too! You can rapidly export or batch convert files to the MP3, AAC, Apple Lossless, FLAC, AIFF, and WAV formats.

Read on or just download and start editing now!

Fission 2.2.5
Released September 17, 2015
For Mac OS X 10.9 or higher
Read the release notes

Free Download


Before purchase, audio saved with Fission will be degraded via audio fades.
Purchase a license key for just $29.

Fission 1 user? Click to upgrade to Fission 2.


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Newest Features

  1. Tons of Tweaks Support for MP3 CBR & VBR, HE-AAC, direct import from iTunes, bug fixes, and much, much more.
  2. Import More Fission can now import many more formats, including: MPEG layer 1 and 2, AIFF-C, Ogg Vorbis, Shorten, RealAudio, Windows Media Audio (WMA), AMR, QDesign Music, WavePack and Monkey's Audio.

New in Fission 2

  1. New Badge Icon A Whole New Look Fission's interface has been updated to make it easier, more fun to use, and a joy to behold.
  2. Cross Format Icon Cross-Format Exporting Edit an AIFF file, then save it to MP3. Edit FLAC and save to AAC. You can now export to any supported format.
  3. SoundCloud Icon Share to SoundCloud When you're done editing, you can publish your audio directly to a SoundCloud account. Sharing is a snap!
  1. Multiple Windows Icon Multiple Windows Want to edit multiple audio files at once or just copy and paste between files? With Fission 2, you can!
  2. Batch Converter Icon Batch File Conversion Using the new Batch Converter, you can transcode dozens of files between audio formats, with just a few clicks.
  3. FLAC icon FLAC Audio Support Fission now has full support for opening, editing, and saving FLAC audio files.
  1. Magic Wand Icon Modes Be Gone Editing used to mean switching between Inspect, Select, and Split modes. Fission 2 provides access to all controls, all the time.
  2. Chapterized AAC Icon Chapterized AAC Files If you need to make an enhanced podcast with AAC chapters, Fission will have it done in no time flat.
  3. WAV Icon WAV, Too In addition to adding support for FLAC, Fission now supports reading, editing, and saving WAV audio files as well.

Key Features

  1. Easy icon Easy Editing Trim, split, fade in and out, all with a few simple clicks. Fission is designed with simplicity in mind.
  2. Export icon Export to Any Format Fission can now save any file directly to MP3, AAC, Apple Lossless, FLAC, AIFF, or WAV.
  1. icon Quick Audio Removal Cutting out audio couldn't be easier, with Fission's easy selection and cropping.
  2. Native Formats icon Native Format Support Edit natively, with no quality loss, in the MP3, AAC, Apple Lossless, AIFF, and WAV formats.
  1. Batch Converter icon Batch Converter Fission's Batch Converter lets you quickly convert multiple files between audio formats.
  2. Lossless icon No Quality Loss Required Yes, Fission can edit lossily compressed MP3 and AAC files without re-encoding, so you never lose quality.

Common Uses

  1. icon iPhone Ringtones Edit audio down, then choose "Save as iPhone Ringtone" to get ringtones & text tones for the iPhone.
  2. icon Split Up LPs Take one long file, such as a recorded LP, and split it into individual songs.
  1. icon Remove Commercials Trim out unwanted ads and other bits from recordings made in Audio Hijack Pro, Piezo, or other apps.
  2. icon Edit Podcasts Record a podcast with Audio Hijack Pro, then edit it down in Fission.
  1. Convert an Album icon Convert Digital Albums Convert digital downloads from large-file formats like FLAC to more portable formats.
  2. Enhanced Podcasts icon Create Enhanced Podcasts Even better, create Enhanced Podcasts, with chapterized AAC files. It couldn't be simpler.

Fast and Powerful Editing

  1. icon Crop It Out Got a small portion of audio to save? Highlight it, click Crop and you're done.
  2. File Joining icon File Joining With a simple drag and drop or copy and paste, you can join two or more files.
  3. Smart Split icon Smart Split Automatically split files based on silence - perfect for LP and DVD recordings.
  1. Gain Adjustment icon Inline Gain Adjustment Highlight a section of audio then adjust the gain with the Gain slider.
  2. Remove icon Trim Audio Out Highlight unwanted audio, then press delete - that's it.
  3. Fade In icon Fade Away Fade audio in and out to create pleasing transitions.
  1. icon Why Be Normal? Give audio files a constant volume level with the Normalize function.
  2. Split icon Split Points With Fission's Split Points, you can split and save to get multiple files.
  3. icon Precise Splits Move split points by dragging exactly where you like, or add by timestamp.

Many More Features

  1. iTunes icon Edit iTunes Downloads If you buy songs from the iTunes Music Store, Fission can help losslessly edit it.
  2. Cue Sheet icon Cue Sheet Support Split files using cue sheets, or export your edits to a cue sheet file.
  1. icon Update ID3 Info Update the track info, as well as artwork and lyrics, for all audio formats.
  1. Info icon Detailed File Info The Summary view shows detailed information for your audio files.

User Quotes

I didn't really realize valuable your straight-forward interfaces in Fission would be for breaking an audio recording into segments. I recently did a breakdown of Ben Bernanke's 60 Minutes interview for example, quickly chopping the file into some 96 segments. I started out in GarageBand, but it was taking so much longer to accomplish the task that (being familiar with how fast you can do this in Fission) I opened the file in Fission and just started over. I was done in one quick pass, and no kidding, in maybe 10 percent or 20 percent of the time or effort it was taking in GarageBand.

—Mike M.

It's beautiful. You guys are artists.

Merlin Mann

See more praise…

Goes Great With...

Audio Hijack iconAudio Hijack

Need to record audio from a mic or an application? Try out Audio Hijack. Save big with the Audio Hijack + Fission bundle in our store!