Join MP3, WAV, M4A, FLAC and other recordings in the exact order you choose. Insert silence or blend tracks with a crossfade, then export one MP3 or WAV — entirely in your browser.
MP3 · WAV · M4A · AAC · OGG · Opus · FLAC · WebM · AIFF
An audio joiner is useful for assembling interview answers, podcast sections, voice notes, language exercises or a sequence of songs. Each source appears in a numbered list, so the order is explicit before processing begins. You can preview every item and remove or rearrange it without decoding the entire set again.
Joining raw bytes only works when every source has the same codec settings. This tool instead decodes each file, matches its sample rate and channel layout, then writes a fresh output. That makes combinations such as M4A plus WAV or mono speech plus stereo music predictable rather than producing a file that changes speed halfway through.
A zero-second transition places tracks directly beside each other. A silent gap is useful between lessons or spoken chapters. A crossfade overlaps the end of one track with the start of the next and blends them linearly, which is often smoother for music. To remove unwanted intros first, use the audio cutter; to break a long recording into chapters, use the audio splitter.
Yes. Each source is decoded first, so MP3, WAV, M4A, AAC, OGG, Opus, FLAC, WebM audio and AIFF tracks can share one output when the browser supports their codecs.
The merger matches every track to the first file’s sample rate and to a common mono or stereo layout before joining them. This prevents a 44.1 kHz track from playing at the wrong speed after a 48 kHz track.
Yes. Use the up and down buttons beside each track. The numbered list is the exact playback order used in the merged file.
Yes. Add up to 30 seconds of silence, or overlap adjacent tracks with a crossfade of up to 10 seconds. Choosing one automatically clears the other.
No. Decoding, resampling, crossfading and encoding happen inside the browser. Nothing is sent to filetools.co or stored on a server.