Cut and Merge Audio Online: Trim MP3 & Join Multiple Files Free

Need to cut a part of an MP3 or merge several audio files into one? You can do both online, in your browser — no installation and no sign-up. MP3 Toolbox now includes a Cut MP3 tool (trim by waveform and time) and a Merge Audio tool (join up to 5 files in order). This guide explains how to use each one and answers common questions.

Cut MP3 Online (Trim Audio by Waveform)

The Cut MP3 tool lets you trim an MP3 file by choosing exactly where to start and end. You see a waveform of your audio and can drag the selection handles or type start/end times. Only the selected part is kept; the rest is removed. Perfect for removing intros, outros, silence, or saving a single segment from a long recording.

How to Cut (Trim) MP3 on MP3 Toolbox

1. Open the Cut MP3 tool — Go to Cut MP3 on MP3 Toolbox.
2. Upload your file — Drag and drop your MP3 or click to browse. Max 100MB. The waveform loads and shows the full track.
3. Set the segment to keep — Use the orange region on the waveform: drag the left handle for start time and the right handle for end time. You can also type times in the Start and End fields (e.g. 1:30.0). Click on the waveform to seek; use the play button to hear the selection.
4. Choose output format (optional) — The dropdown lets you save as MP3, M4A, WAV, FLAC, OGG, OPUS, and more. Default is MP3.
5. Save and download — Click Save. The trimmed file is generated and you download it. Files are deleted from our servers after 15 minutes.

👉 No account, no watermarks. Works on desktop and mobile.

Merge Audio Online (Join Multiple Files)

The Merge Audio tool joins 2 to 5 audio files into a single file, in the order you upload them. Each file is shown in its own waveform box so you can confirm the order and play each track before merging. Useful for combining podcast segments, song parts, or voice clips into one continuous file.

How to Merge (Join) Audio Files on MP3 Toolbox

1. Open the Merge Audio tool — Go to Merge Audio on MP3 Toolbox.
2. Upload 2–5 files — Drag and drop or click to select 2 to 5 audio files at once. Supported formats include MP3, M4A, WAV, OGG, FLAC, OPUS, AIFF, WMA, and CAF. Each file appears in its own box with a waveform.
3. Check order and preview — Files are merged in the order shown (1, 2, 3…). Use the play button on each track to listen and confirm it’s the right file and order.
4. Choose output format — Select the format for the merged file (MP3, M4A, WAV, FLAC, etc.).
5. Merge and download — Click Merge. The combined file is created and you download it. Uploaded and output files are automatically removed after 15 minutes.

👉 Same as Cut: no sign-up, no software, free to use.

When to Cut vs When to Merge

• Cut (trim) — You have one file and want to keep only a part of it (e.g. remove intro/outro, extract a clip, remove silence).
• Merge (join) — You have several files and want one continuous file (e.g. combine podcast parts, stitch song sections, create a single mix).

You can use both in sequence: cut each file first if needed, then merge the trimmed clips.

FAQs

Do I need to create an account?

No. Both Cut MP3 and Merge Audio work without sign-up or login.

What file formats are supported?

Cut MP3 accepts MP3 input; output can be MP3, M4A, WAV, FLAC, OGG, OPUS, AIFF, WMA, or CAF. Merge Audio accepts common audio formats (MP3, M4A, WAV, OGG, FLAC, etc.) and outputs in the same range of formats.

Is there a file size limit?

Yes. Each file is limited to 100MB. For merge, the total of all uploaded files should be within reasonable size for processing.

Are my files stored or shared?

No. Files are processed on our servers and automatically deleted after 15 minutes. We don’t keep, sell, or share your audio. See our Privacy Policy for details.

Can I reorder files before merging?

Merge order is the order in which you select or drop the files. To change order, refresh the page and upload the files in the desired sequence.

Does cutting or merging reduce quality?

For Cut MP3, when output is MP3 we use stream copy where possible, so no re-encoding. For other formats or for Merge, audio is re-encoded; we use high-quality settings so quality loss is minimal for typical use.

Try Cut and Merge Now

To trim an MP3 by waveform and time: use Cut MP3. To join 2–5 audio files into one: use Merge Audio. Both are free, work in the browser, and require no account or software.