1Upload every file you want combined — at least two of them.
2Drag the uploaded items into the order you want; the order is taken from the list, not from the filenames.
3Start the merge, which joins matching inputs without re-encoding them and reconciles mismatched ones exactly once.
4Download the single combined Audio file.
Merge Audio FAQ
How does Merge Audio join the files together?
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Concretely, matching inputs are concatenated by copying encoded frames and mismatched ones are normalised once, so the join is as cheap as the source material allows. Upload everything you want combined and the result comes back as a single file.
Can I control the order things are joined in?
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Yes — drag the uploaded items into the order you want before starting. Order is taken from the list, not from the filenames, so "track2.mp3" sorting after "track10.mp3" is not a problem you have to solve first.
Does it matter if the inputs are different formats?
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It does. this format is read and written by the same streaming pipeline as everything else we support. Matching inputs take a fast, lossless path; mismatched ones have to be reconciled to a common format, which is slower and costs one encode.
Anything specific to Audio when merging?
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Yes — the codec is detected from the stream, so a mislabelled extension does not derail the job. That is worth checking when the inputs did not all come from the same source.
How many files can I combine at once?
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On the free tier a merge accepts two files at a time, which is deliberately higher than the single-file limit on other tools because merging one file is meaningless. A pass removes the cap entirely.
Is the merge lossless?
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It is whenever the inputs already agree — the encoded data is copied straight through. It stops being lossless only when the inputs disagree and something has to be re-encoded to make them compatible, and even then it is one pass, not one per file.
Which audio formats does Merge Audio accept?
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MP3, WAV, AAC, M4A, FLAC, OGG, Opus, WMA and AIFF. Codecs are detected from the stream rather than the extension, so a mislabelled file still works and a mixed batch is handled per file.
Is there a file size limit on Merge Audio?
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Yes: free accounts process audio up to 200 MB per file whichever codec you brought; ffmpeg handles the decode and encode. In practice that limit only bites on uncompressed WAV; a compressed file of the same length is nowhere near it.
Will Merge Audio lower the quality of my audio files?
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It depends on the source. Lossless input (WAV, FLAC, AIFF) is edited sample-exactly and loses nothing. Lossy input has already discarded detail once, so where the job can be done by copying the encoded stream rather than re-encoding it, that is the path taken.
Can I run Merge Audio on several audio files at once?
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Yes. The set queues in parallel with identical settings, which is how you process an album or a podcast back catalogue without repeating yourself.
Do tags and cover art survive?
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Yes — ID3, Vorbis comments and MP4 atoms are carried across along with embedded artwork, so processed files still sort correctly in a music library.
Does Merge Audio cost anything?
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No. Merge Audio is free with no account, and nothing is added to the audio. Uploads are deleted from the workers shortly after the job completes.
