Trim AIFC

How to Trim AIFC Audio Online

1. Upload Your AIFC File: Click "+ Add Files" or drag and drop your .aifc (AIFF-C) file. Batch upload is supported — queue up several legacy Mac recordings and trim them with the same in/out points.
2. Set Trim Points: Under "Trim," enter a start time and duration in HH:MM:SS.mmm. Start at 00:00:05.000 with duration 00:00:30.000 keeps a 30-second clip beginning at the 5-second mark.
3. Adjust Compression and Audio (Optional): Under "File Compression," pick "Quality Preset" (Highest, Very High, High, Medium, Low, Very Low, Lowest), "Constant Bitrate" (e.g., 128 kbps fixed), or "Variable Bitrate" (range like 128k–160k). Set "Audio Channel" to Mono or Stereo, and "Audio Sample Rate" (8000 Hz up to 48000 Hz).
4. Trim and Download: Click "Trim." Your file is processed in your browser session — no sign-up, no watermark, and the original file never leaves the page.

Why Trim AIFC Files?

AIFC (also written AIFF-C) is the compressed sibling of Apple's Audio Interchange File Format. AIFF, released by Apple in 1988, stores uncompressed PCM. The AIFF-C extension was introduced in July 1991 to add codec support inside the same FORM container — the file's outer chunk type is AIFC instead of AIFF, and the COMM chunk carries a four-byte compression type ID like sowt, ulaw, alaw, ima4, MAC3, MAC6, fl32, or fl64. Notably, when iTunes (now Apple Music) imports or exports a CD as "AIFF," the file written to disk is actually AIFF-C with the sowt (little-endian PCM) tag.

Trimming AIFC keeps you inside the AIFF-C container so the original codec, sample rate, and Mac OS metadata are preserved — useful when you only need a clip and want to avoid a re-encode.

• Cut intros and trailing silence from legacy Mac recordings — Old QuickTime, HyperCard, and System 7 audio archives often have several seconds of room tone or a count-in. Trim those out without converting the codec.
• Extract a sample from a longer voice memo or interview — Voicemail systems and dictation software historically wrote AIFC with MACE 3:1 or IMA 4:1 to save space. Pull a single quote without touching the rest.
• Prep clips for Logic Pro or GarageBand import — Apple Loops and project audio inside Logic Pro and GarageBand use AIFF/AIFF-C as a native format. A pre-trimmed AIFC drops onto the timeline at the right length.
• Slice game audio assets — Classic Mac games and emulator soundtracks often ship audio in AIFC with ima4. Trim to loop boundaries without re-encoding.
• Preserve scientific or field-recording archives — Bioacoustic and linguistic field recordings stored as AIFC keep their fl32 floating-point data through a trim, so dynamic range stays intact.
• Share a 30-second excerpt by email — Most email providers cap attachments around 25 MB (Gmail, Outlook). A trimmed AIFC clip easily fits where the full archive would not.

AIFC vs AIFF vs WAV

Property	AIFC (.aifc)	AIFF (.aiff / .aif)	WAV (.wav)
Created by	Apple, 1991	Apple, 1988	Microsoft & IBM, 1991
Container chunk ID	FORM / AIFC	FORM / AIFF	RIFF / WAVE
Compression	Codec ID in COMM (PCM, MACE, IMA4, ulaw, alaw, fl32, fl64)	Uncompressed PCM only	Mostly PCM; supports codec tags
Byte order	Big-endian; sowt = little-endian PCM	Big-endian PCM	Little-endian PCM
Typical use today	Legacy Mac archives, iTunes CD imports	Mac/pro audio masters	Windows/cross-platform audio
Native Apple support	iTunes/Music, QuickTime, Logic Pro, GarageBand, Audacity	Same	Same

AIFC Compression Codec Quick Guide

Codec ID	Name	Ratio vs PCM	Typical use
NONE / sowt	Uncompressed PCM (big- / little-endian)	1:1	iTunes CD imports, masters
fl32 / fl64	32- / 64-bit floating-point PCM	1:1 (larger)	Scientific recording, mastering
ulaw / alaw	G.711 µ-law / A-law (8-bit log PCM)	~2:1	Telephony, voicemail
ima4	IMA ADPCM 4:1	4:1	Old Mac games, QuickTime
MAC3	MACE 3:1	3:1	Classic Mac OS voice
MAC6	MACE 6:1	6:1	Classic Mac OS voice (lossier)

When you trim, XConvert re-muxes within the AIFC container. If you change the "File Compression" setting, the output is re-encoded at that quality preset or bitrate — leaving compression on "Original/Unchanged" preserves the source codec.

Frequently Asked Questions

Why does my file end in .aifc instead of .aiff?

Apple's authoring tools and iTunes/Music sometimes write the AIFF-C container even when labeling the file "AIFF." The four-character form type inside is AIFC, and the file may carry a compression tag like sowt (little-endian PCM) or ima4. Some apps key off the extension, which is why renaming .aiff to .aifc (or vice versa) doesn't always work — the chunk header has to match.

Will trimming re-encode my AIFC file?

If you leave "File Compression" on the original/unchanged setting, the trim is a stream copy — the same codec, sample rate, and bit depth come out the other side. If you switch to a different Quality Preset, Constant Bitrate, or Variable Bitrate, the audio is re-encoded at that target.

Can I trim AIFC files containing MACE or IMA compression?

Yes. The trimmer reads the COMM chunk to detect the compression type, decodes that range, and writes a valid AIFC back out. MACE 3:1, MACE 6:1, IMA 4:1, ulaw, alaw, and PCM variants are all handled.

What sample rate and bit depth should I keep?

Match the source. Apple Music CD imports are 44100 Hz, 16-bit, stereo. Pro Tools and Logic sessions are typically 48000 Hz, 24-bit. Voice and telephony AIFC are often 8000 Hz or 22050 Hz. Resampling to a different rate adds a conversion step you usually don't need for a trim.

Should I keep AIFC or convert to a modern format?

Keep AIFC if the file is going back into Logic Pro, GarageBand, Final Cut Pro, or a Mac archive that expects it. Convert to FLAC if you want lossless compression with broad modern player support, WAV for Windows/cross-platform PCM, or MP3 for universal sharing and email attachments.

Why is AIFC so much larger than MP3 or AAC for the same length?

AIFC's most common compression types (PCM, sowt, fl32) are not perceptual codecs — they don't discard inaudible audio the way MP3, AAC, or Opus do. A 3-minute stereo AIFC at 44100 Hz, 16-bit PCM is around 30 MB; the same content as a 192 kbps MP3 is about 4 MB. Even MACE 6:1 only gets AIFC down to ~5 MB, and quality is much worse than a modern lossy codec.

What software opens trimmed AIFC files?

Apple Music, QuickTime Player, Logic Pro, GarageBand, and Final Cut Pro on macOS open AIFC natively. Cross-platform: VLC, Audacity, and Adobe Audition. Most Windows media players will open uncompressed AIFC (PCM/sowt) but may not decode older Apple-only codecs like MACE — convert to WAV or FLAC if you hit a "codec not supported" error.

Can I trim more than one AIFC at the same trim points?

Yes. Drag in multiple files and the same start/duration applies to each output. Useful for cropping silence off a folder of takes from a single session or extracting matching segments from multitrack stems.

What's the maximum file length I can trim?

There's no hard length cap from the AIFC container itself — FORM chunks support sizes up to 2 GB in practice. Browser memory is the practical limit, since trimming runs entirely in your browser session. Files in the hundreds of MB work; multi-gigabyte session files may need to be handled in a desktop editor.

How is this different from the audio trimmer?

The general audio trimmer auto-detects the input format from the file extension. This page hard-binds to AIFC and surfaces the AIFF-C–specific compression options (codec preservation, sample-rate handling for sowt and fl32). If you have AIFF instead of AIFC, use trim AIFF.