How to Cut or Trim an Audio File Online: Free MP3 Cutter, No Upload

Cutting an audio file to a specific section comes up constantly: trimming a podcast intro, isolating a quote from an interview recording, making a ringtone from a chorus, or shortening a voice memo before sharing it. The tools that handle this range from basic browser extensions to full digital audio workstations — but for a one-off trim, you don't need any of that overhead.

Cut Audio in Your Browser (No Upload)

1. Go to convertlo.pro/audio-cutter.html
2. Drop in your audio file — MP3, WAV, M4A, OGG, FLAC, AAC, Opus, or WMA
3. The file loads into an audio player showing total duration
4. Play the audio to where you want the clip to start, then click "Set to current" next to the start field (or type the time directly in seconds)
5. Repeat for the end time
6. Click Cut — the tool first tries a fast, lossless cut; if that's not possible for the format, it re-encodes automatically using the matching codec (libmp3lame for MP3, pcm_s16le for WAV, AAC for M4A/OGG/others)
7. Download the result — same format as the source, just shorter

Common Use Cases for Cutting Audio

Making a ringtone

Pick a 15-30 second hook or chorus from a song. For iPhone, export as M4A, then rename the file extension from .m4a to .m4r — iOS recognizes .m4r files as ringtones and syncs them through Finder (drag the file onto your device in Finder's Sounds tab). The clip must be under 40 seconds for iOS to accept it as a ringtone. For Android, most audio formats including MP3 and OGG can be set directly as a ringtone or notification sound through the phone's sound settings — no rename needed.

Trimming a podcast or interview clip

If you only need a 30-second soundbite from an hour-long recording, cutting first dramatically reduces the file size you're sharing or uploading elsewhere. Cut the relevant section, then if you need to share it on a platform with format restrictions, convert it separately afterward.

Shortening a voice memo

Voice memos recorded on iPhone are AAC-encoded M4A files. Convertlo's Audio Cutter handles M4A natively — cut the relevant portion before sharing, since the rest of a long memo often contains pauses, false starts, or irrelevant context you don't want to send.

Extracting a sound effect or sample

For short, precise samples (a single sound effect from a longer recording), the ±keyframe imprecision of fast trim usually doesn't matter for casual use, but if you're sampling for music production, expect a small re-encode step for sample-accurate boundaries.

Lossless Cut vs. Re-encode: Why It Matters for Audio

Like video, audio formats store data in frames, and a "fast" cut works by copying existing encoded frames without touching their content. For formats like MP3, cutting on a frame boundary (which most cutters do automatically) produces a byte-for-byte identical result for the retained audio — there's no quality change at all.

Re-encoding becomes necessary in a few cases: when the cutter needs to apply a fade-in/fade-out for a smoother transition, when the target format doesn't support easy frame-accurate stream copy (some WAV and FLAC edge cases), or when the desired cut point falls in the middle of a frame and the tool prioritizes precision over speed. The quality impact of one re-encode pass is typically inaudible for casual listening, but for archival-quality audio, a lossless cut should always be preferred when available.

Cutting Audio from a Video File

If your source is a video and you want a short audio clip from it, there are two valid orders of operations:

• Extract first, then cut: Use Convertlo's MP4 to MP3 converter (or see the Extract Audio from Video guide) to pull out the full audio track, then run the result through the Audio Cutter.
• Trim first, then extract: Use the Video Trimmer to cut the video down to the relevant time range first, then extract audio from the shorter clip. This is faster if the source video is very large, since you're not extracting audio from the entire file.

Desktop Methods (No Upload Required)

Audacity (Free, Cross-Platform)

Audacity is the standard free, open-source audio editor. Open your file, select the region you want to keep by dragging across the waveform, then Edit → Clip Boundaries → "Trim Audio" (or use Generate → Silence to remove unwanted sections). Export as MP3, WAV, or other formats. Fully offline.

ffmpeg (Command Line, Lossless)

ffmpeg -ss 00:00:30 -i input.mp3 -t 00:00:45 -c copy output.mp3

This starts at 30 seconds, copies 45 seconds without re-encoding (lossless for MP3), and writes output.mp3. For WAV files, the same command with -c copy works because WAV is uncompressed PCM — there's nothing to re-encode.

Frequently Asked Questions