Fission is a streamlined audio editor designed to get you editing in minutes, not hours. It works with MP3, AAC, Apple Lossless and AIFF audio (in both mono and stereo), enabling you to instantly trim and split files with no quality loss.

Features

• Edit MP3, AAC, Apple Lossless, and AIFF files with no quality loss
• Quickly split a long audio file into smaller files
• Remove unwanted content, such as commercials, from your audio file
• Create great-sounding MP3 or AAC ringtones for your cell phone.

New in v2.2.5

• Improved file support for several different file types.
• Faster loading of AAC and Apple Lossless
• Improved support for Apple Lossless files including the rare 20-bit ALAC format.
• Improved Tag support for FLAC files
• Rounding out our improved file support, chapterized AAC files are now better supported as well.
• Fission is now fully certified for use with Mac OS X 10.11 (El Capitan).
• Fission now requires Mac OS X 10.9 (Mavericks) or higher.
• Various other minor fixes and improvements

New in v2.1.4

• Now a 64-bit application.
• Full support for developer preview versions of Mac OS X 10.9 (Mavericks).
• The QuickTime engine for opening file has been replaced with our own internal libav.
• New saving pipeline.
• Bug fix for song dragging iTunes into the Mac App Store version of Fission.
• Overhauled the License window with HTML.
• Chapters which contain multiple images now grabs the first image in the chapter.
• New hidden "Check for News" option, accessible by pressing option while in the Fission menu.
• Slimmed down debugging window.
• Now better handles excessively large AAC and Apple Lossless files.
• Various other minor improvements.

New in v2.1.3

• Fix for CPU handling issue
• Better handles UTF-8 in ID3 tags.
• Updated batch converter
• Moving the playhead no longer dirties a file.
• Fixed crash when inserting silence
• Now handles .m4a_partial files, to recover corrupted AAC files.
• VoiceOver improvements
• Channels selector now properly appears for mono files
• Clip tabs now always show the clip name.
• Fixed issue where some FLAC files don't open properly
• Various other bugfixes and improvements

New in v2.1.1

• Bugfix for issue with chapterized AACs and very large image files
• Fission's Batch Converter now accepts folders (containing audio files), as well as individual files.
• The Save panel now correctly remembers the last location to which files were saved.
• Fission now has a hidden preference, accessible via the Debugging window, to check for and prevent rare Normalization clipping.
• Bugfix for an issue where attempting to Save (with Cmd-S or by choosing Save) would cause an error for users of the Mac App Store version
• Various bugfixes

New in v2.0

• Revamped interface
• Open multiple audio files at once, in multiple windows.
• Now supports editing FLAC and WAV files. MP3, AAC, Apple Lossless, FLAC, AIFF, and WAV
• Export to another format
• The new Batch Converter makes it possible to convert multiple files to another format with just a few clicks.
• SoundCloud support is now built right in to Fission, to make it a snap to share your files on the web.
• Fission can now quickly save Chapterized AAC files, for creating enhanced podcasts.
• Fission now uses our new manual system, with improved navigability. It is now also searchable.
• Fission's icon has been updated for full Retina compatibility, and throughout the site. The app itself will be updated for Retina in the future.
• We've also made too many other small improvements and fixes to list.