Will merging reduce the quality?

If your files share the same format, Sondra joins them without re-encoding, so quality is unchanged. If they differ, it converts them to a single consistent track.

Is my audio uploaded to a server?

Never. Everything runs locally in your browser. Your files never leave your device.

Can I merge files in different formats?

Yes. Sondra automatically matches different formats so they join into one smooth track.

What order will the files play in?

They play from top to bottom in the list. Use the up and down arrows to set the order before merging.

How many files can I merge?

As many as you like, as long as the total size stays under the limit, which is 500MB on desktop and 100MB on mobile.

Yes. Merging audio on Sondra is free, with no signup and no watermark.

Can I merge audio on my phone?

Yes. Sondra works in mobile browsers, with a 100MB total limit on mobile.

Is there a limit on how many files I can join?

There is no fixed limit on the number of files. The only limit is the combined size: up to 500MB on desktop and 100MB on mobile.

Does it work without internet?

After the page has loaded once, the merging itself runs offline in your browser. You only need a connection to open the page the first time.

Merge Audio Online and Join MP3 Files

Combine several audio files into one track. Drag them into order, then merge. Free, private, and right in your browser.

Drop audio files here or click to upload

MP3, WAV, AAC, FLAC, M4A, OGG

Up to 500MB total on desktop, 100MB on mobile

Fast 100% private Free

How to merge audio

Add your files

Drop in or pick the audio you want to join. It stays on your device.

Put them in order

Use the arrows to arrange the files in the order you want them to play.

Merge and download

Join them into one track and save the result.

Why merge audio?

Join songs into a mix, combine voice memos, stitch podcast segments, or build one long track from several files. Sondra joins them back to back in the order you choose.

When your files share a format, Sondra joins them instantly. When they differ, it converts them into a single consistent track so the result plays smoothly. Everything happens in your browser, so your audio is never uploaded.

Sondra works with MP3, WAV, AAC, FLAC, M4A and OGG, joins your files in the exact order you set, and never adds a watermark. Open the page, add your audio, arrange it, and download one combined track in seconds.

What you can do by merging audio

Joining audio files into one track is handy in lots of situations. Here are the most common ones.

Make a music mix

Combine several songs into one continuous mix or playlist file.

Join podcast segments

Stitch intro, interview and outro into a single episode ready to publish.

Merge voice memos

Put separate recordings or notes back to back into one file.

Build a long track

Combine short loops or clips into one longer audio file.

Merge audio for any use

A merged MP3 plays everywhere. A few notes for the most common uses.

Podcasts

Join your segments into one MP3 before uploading to your host.

Music players

Combine tracks into a single file that plays as one continuous mix.

Phone and messaging

The merged file plays in any music or messaging app, with no extra app needed.

Video editing

Merge narration and music into one audio track to drop onto your timeline.

Private by design

Most online joiners upload every file to a server before combining them. Sondra does not. All the work happens inside your browser on your own device, so your audio is never sent anywhere and nobody else can hear it.

That also means there is no waiting for a long upload, no account to create, and no limit on how many files you join. Close the tab and nothing is left behind.