Fission is an audio editor designed with simplicity in mind. With it, you can quickly and easily trim and split audio files, all with no quality loss. You can also export from one format to another, batch convert a group of files, and even create iPhone ringtones. Fission makes audio editing simple, fast, and affordable.
This manual provides you with a useful overview of the application, including an outline of the interface, as well as details on using the application. We recommend a quick read-through, but you can also just dive in if you like. Refer back to this online manual for assistance at any time, right from Fission's Help menu.
The following resources will supplement a read-through of the manual and help you get the answers you need.
This manual is part of our searchable Fission Support Center, which also provides answers to common questions, as well as tutorials, tricks, and more.
Rogue Amoeba's top-notch Support team is always ready to assist, both before and after purchase. Select Contact Support in the Help menu to get in touch. We're amazingly responsive, and strive to reply within 24 hours.
If you've used Fission before, this information should prove helpful.
The Release Notes window always provides a comprehensive list of improvements and fixes made to Fission. Access it from the in-app Help menu.
If you purchased a license for Fission 1, you're eligible for a heavily discounted upgrade to Fission 2.
Get started with details on the main Fission controls, as well as its basic functionality.
Fission's Editing Window
Fission's editing window contains all the controls for editing audio. Here, audio can be selected and removed, split points can be added, and volume levels can be adjusted. For more details, see all the pages in the “Editing Operations” section.
Fission's Inspector
When an audio file is open, the Inspector can be shown on the right side of the window. Here, metadata can be updated, including ID3 tags, lyrics, and artwork. Information on the file, including bitrate, sample rate, and more, can also be found under the Summary tab.
Fission's Batch Converter
Fission's Batch Converter makes it a snap to convert between audio formats. Drop as many audio files as you like onto the Batch Converter, then select the format to which you'd like to convert them. Click Convert, and Fission does the rest. Learn more on the Converting Formats page.
Fission can be used to remove audio from a file, as well as add new audio.
Deleting audio is as easy as selecting and removing it. First, select the exact audio you wish to remove. You can tweak your selection by dragging either edge to increase or decrease the length. Alternately, the Set Selection option in the Tools menu will let you select an exact length of audio.
A selection of audio to be removed
Once the audio is selected, you can delete it by clicking the Remove button in the toolbar, or by selecting Remove from the Clip menu. The selected audio will then be removed from the file. If you wish to automatically add fades into and out of the removed point, turn on the Fade Around Removed Audio option in the Clip menu. For more details on fading, see the Fades and Volume Adjustments page for details.
Remove & Split button
You can also use the Remove and Split function in the Toolbar or Clip menu, to add a split point between two pieces of audio. For more on split points, see the Splitting Audio page.
Cropping audio is also very straightforward. First, select the audio you wish to keep. Remember that you can tweak a selection by dragging either edge to increase or decrease the length, or set an exact selection with the Set Selection option in the Tools menu.
The Crop Button
Once the exact selection is made, the audio can be cropped by clicking the Crop button in the toolbar, or choosing Crop from the Clip menu. All other audio will be removed, leaving you with only the selected audio.
Audio can be added to a file in two ways. First, if you wish to simply join two (or more) files together, you can drag and drop a file from the Finder into an already-open audio file. The second file will be added to either the beginning or end of the open file (depending on where you drop) as a separate clip, so that it can be easily moved and manipulated. To merge the two clips together, just highlight the split point separating them, and delete it.
Two files can easily be joined into one
Audio can also be pasted in between audio files. With multiple audio files open, you can select audio from one file and copy it out using the Edit menu. Switch windows to the destination file, and paste it in where desired. The audio will be inserted wherever the playhead is currently located, as a separate clip. Again, to merge the two clips together, just highlight the split point separating them, and delete it.
Finally, Fission can add periods of silence to files, with the Insert Silence command. The Insert Silence sheet will appear:
With the settings seen above, 11.34 seconds of silence will be inserted where the playhead is currently located. Note that silence is added as a separate clip, so that it can be easily moved and manipulated. To merge the silence fully, just highlight the split points and delete them.
Fission can help you rapidly split one long audio file into multiple files.
Fission uses split points, or splits, to separate clips in an audio file. When a file contains multiple clips, the split points are what separate each clip. Saving a file with multiple clips results in multiple audio files being saved out.
To adjust the length of a clip, just move the relevant split by clicking and dragging it to the desired point. To merge two clips together, just remove the split point separating them by clicking it to highlight, then pressing the delete key on your keyboard. You can also remove all splits from a file by selecting Clear All Splits from the Edit menu.
A split point between two clips
Adding a split point can be done in several ways. Generally, placing the playhead where you wish to split is the first step. You can click once in the main waveform to move the playhead, or simply play the file until the desired point. Once the playhead is in place, you can click the Split button in the Toolbar, or select Split at Playhead from the Clip menu. A split point will be inserted into the file, separating the audio into two distinct clips.
If you know the exact timestamp where you'd like to split, you can also use the Add Split option in the Tools menu to add a precise split.
You may wish to remove a split point, to prevent separate files from being saved out. To remove a split point, just click it, then press Delete on your keyboard or choose Delete from the Edit menu. Alternately, you can choose Clear All Splits from the Edit menu to remove all splits at once.
Fission's Smart Split tool can be used to automatically find split points in a file, based on where there are silences. This can be particularly useful for rapidly splitting up recordings from analog sources like records and tapes, as well as multi-song digital recordings. To access it, select Smart Split from the Tools menu:
Fission's Smart Split Window
Smart Split identifies silences based on the settings selected and shows where it will place split points. When you click the Insert Splits button, the split points will be added to the file, creating multiple clips. If needed, adjust these splits by moving them, adding more, or removing any which are erroneous. Once you've got the split points set, save the audio out and you'll get a distinct file for each clip.
Fission can fade audio in and out, normalize an entire file, and adjust the gain of a portion of audio.
To fade audio, start by selecting the audio you wish to fade. Once a selection is made, click the Fade In or Fade Out buttons to fade the audio across the entire selection.
Fission's Fade Buttons
As well, with the Fade Around Removed Audio option turned on in the Clip menu, you can set Fission to automatically fade around areas where audio has been removed. The duration of these fades can be adjusted in the Settings window.
Fission's Normalize Button
Normalize increases the gain of the selected audio, so that the loudest sample is at set to the maximum possible value. This makes the selection as loud as possible without causing distortion. To normalize a selection of audio, just highlight the desired audio then click the Normalize button.
Fission's Gain Adjustment Slider
You'll see the Gain Adjustment button at the bottom of any selection. Clicking and holding the button will bring up the Gain Adjustment slider. Just slide up or down to adjust the gain of the selection.
While originally designed for lossless audio editing, Fission can also save audio between formats in a process known as transcoding. For example, you can edit an AIFF file and save it to MP3, or take a collection of FLAC files and convert them to AAC. Fission offers two ways to convert formats: you can export a single file to a new format, or perform a batch conversion of many files at once.
Fission offers support for saving to MP3, AAC, Apple Lossless, FLAC, AIFF, and WAV, with defaults offering varying quality levels. Audio experts can even customize all settings using the Custom menu option. Remember that higher bitrates provide higher quality, but also create bigger files. For more details, see our supported audio formats article.
When you've got an audio file open, selecting Export from the File menu will bring up this sheet:
From this sheet, you can export a file to your desired format and Fission will save it out in seconds. You can also export just a selection of a file, with the Export Selection option.
Fission's Batch Converter makes it easy to transcode multiple files at once. The Batch Converter can be opened from Fission's Start window, or by selecting Show Batch Converter from the Window menu.
In the Batch Converter window, you can add multiple files to the table at the top, then select the desired format and output location. Once that's set, clicking Convert will cause the files to be converted in sequence.
iOS devices allow you to set custom tones to play when you receive a phone call or text message, as well as when an alarm or timer goes off. With custom tones, you can assign specific sounds or music to individuals, so you can tell who's calling or texting without even looking at your phone. You can even pick music to wake up to — rise and shine with your favorite song, or force yourself out of bed with music you despise.
Fission enables you to transform any audio file into a tone for use on any iOS device. While these custom tones are often referred to as “iPhone ringtones”, they work great with the iPad and iPod Touch as well.
A custom tone, cropped and ready for saving
The process for making custom tones has varied in recent years, due to changes made by Apple, but Fission has always kept up. For current details, please see the support Knowledge Base article on our website.
Fission has support for saving Chapterized AAC and Chapterized MP3 files. These are audio files which contain distinct sections, known as chapters. Chapterized files are often used by podcasters to make enhanced podcasts.
Visit our support Knowledge Base to read a detailed article on making Chapterized files with Fission.
Fission's settings can be accessed from the Fission menu.
Fission's Settings window
Fade around removed audio: This setting adjusts the length of audio automatically faded in and out when removing a section of audio from a file, when the Fade Around Removed Audio option in the Clip menu is on. The time length of fades can be adjusted with this setting. To prevent automatic fades altogether, turn the Fade Around Removed Audio menu option off.
Play audio through: Adjust this to change the output device through which audio from Fission plays.
Audio Scrubbing: When this setting is active, audio near the playhead will be heard as the playhead is moved.
Theme Selector: This setting dictates how Fission will appear. The Dark theme is perfect for use in darkened spaces like theaters, while the Light theme is designed for brighter spaces. Of course, either can be used in any setting, according to your taste.
The default Match System setting follows the OS-wide Appearance setting for Light or Dark Mode. You can alternately force Fission to use the Light or Dark theme, regardless of your system-wide settings.
Fission's Dark theme
Fission's Light theme
While this manual uses the Dark theme throughout, you can easily try either theme. Fission will update immediately when you adjust this setting.
Automatically check for software updates: With this option activated, Fission compares itself to the most current version available from our server and alerts you when a new version is available. Leave this on and Fission will help you stay up-to-date.
To initiate a check manually, click the Check for Updates… button.
Fission’s Permissions window can be accessed from the Fission menu. This window lists permissions which allow Fission to run optimally.
Fission’s Permissions window
When provided with full disk access, Fission will more readily be able to work with files on external drives. When you click the Enable button in the Full Disk Access section of the Permissions window, you’ll see a brief explanatory dialog:
Follow these instructions to enable Full Disk Access for Fission.
Did you purchase Fission from the Mac App Store? Because we have ceased distributing Fission via the Mac App Store, you should transition to our direct version. This fast and free process takes just a few minutes. See this link for instructions.
Quick Link: To buy a license key for Fission, visit our online store.
Put simply, you should buy Fission because it isn't free. We provide a free trial, so you can test out the program and all its features before you buy it. It's like test driving a car, for as long as it takes you to decide.
In trial mode, all of Fission's features are available to try, but it won't work for full-time use. During the trial, the quality of audio saved through Fission will be degraded through a series of audio fades.
If you use Fission and find you like it, please purchase a license key - support the software you use and love!
To purchase your license key, just visit https://rogueamoeba.com/store/.
If you purchased a license for Fission before April 1st, 2012, you're eligible for a heavily discounted upgrade to Fission 2.
Note: If your license key starts with YELO-, you already own Fission 2 - enjoy!
The download of Fission from our site contains both a free trial of the software and the full version. To unlock the full, unlimited version, you just need a valid license key. When you purchase through our store, you'll immediately receive a license key in your browser as well as via email. Simply enter this key into Fission to unlock it.
While we don't have a hard and fast upgrade policy, our philosophy regarding paid upgrades is simple: We try to do what's right for you and what's right for us. We've got a great track record, with many years of very satisfied customers.
For more details on free updates and paid upgrades, please see this page.
All Rogue Amoeba products are available to try before you buy. We believe that no customer should have to buy software in order to find out how well it works. Our software can be fully evaluated with no limitations in capabilities, prior to purchase. Customers are strongly encouraged to take advantage of these trials prior to purchase. You may also seek any needed technical support from us - we answer support emails rapidly and responsively for current and potential customers alike.
If you would like a refund, please contact our Support Team within 14 days of your purchase. Because we cannot recover the license key that was sold, refunds are issued on a case-by-case basis.
Fission excels at editing existing audio files, but what about recording new files? Whether you need to record audio from a microphone or from an application, Rogue Amoeba has you covered with our own Audio Hijack. All recordings made with Audio Hijack can be edited losslessly in Fission.
Audio Hijack provides powerful audio recording options.
For simple yet powerful recording options, Audio Hijack is the way to go. With Audio Hijack, you can capture from already-running applications, record all System Audio at once, set timed recordings to run when you're not around, record to an enormous variety of recording formats, and more.
Download a free trial right from our site.
To install Fission, drag it from your download folder to the Applications folder, then double-click its icon to begin using it.
If you wish to remove Fission, just quit the application, then place it in the Trash.
If you have any feedback to share, know that we’ll be glad to hear it. Contact us directly to make a feature request, report a problem, or to get assistance. We're always working to improve our products, so please don't hesitate to tell us what was missing or didn't work for you.
Fission (“The Software”) is provided as is. Rogue Amoeba Software (“The Author”) is not responsible for any damage to the user's computer system or data and in no event will The Author, its officers, directors, employees or agents be responsible to the user for any consequential, incidental, or indirect damages (including damages for loss of business profits, business interruption, loss of business information, and the like) arising out of the use or inability to use the The Software, even if The Author has been advised of the possibility of such damages. Because some locations do not allow the exclusion or limitation of liability for consequential or incidental damages, the above limitations may not apply to you. Further, the consumer agrees that using this software in any way illegal, or even for the purposes of assessing its viability for illegal usage, is prohibited.
Be safe when you use the software. Be aware that it's simply a tool designed to make your life better. Don't use it to do illegal or evil things. If you do, be ready to take responsibility for your own actions.
Unless explicitly stated in writing, Rogue Amoeba Software does not grant permission to sell The Software. Non-profit distribution of The Software in its trial form is generally acceptable, provided that The Software is not modified in any way, the complete works of The Software are included in the distribution package, and Rogue Amoeba has been contacted for confirmation.
Don't sell this software. If you wish to distribute it in its trial state, get in touch with us to confirm permission.
Portions of this Rogue Amoeba software may utilize the following copyrighted material, the use of which is hereby acknowledged.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Parts of this product contain certain software owned by FFmpeg and licensed by Rogue Amoeba. You may obtain a complete machine-readable copy of the source code for FFmpeg under the terms of GNU Library General Public License Version 2.1 ("LGPL"), without charge at https://rogueamoeba.com/opensource/.
The FFmpeg software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the LGPL for more details, available at https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
Parts of this product contain certain software owned by Lame and licensed by Rogue Amoeba. You may obtain a complete machine-readable copy of the source code under the terms of GNU Library General Public License Version 2 ("LGPL"), without charge at https://rogueamoeba.com/opensource/.
The Lame software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the LGPL for more details, available at https://www.gnu.org/licenses/old-licenses/lgpl-2.0.html.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the Xiph.org Foundation nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.