1Upload every file you want combined — at least two of them.
2Add the files in the order you want them joined; the first file you add comes first.
3Start the merge; the files are joined one after another into a single file.
4Download the single combined AIFF file.
Merge AIFF FAQ
Does it matter if the inputs are different formats?
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It does. AIFF is Apple's uncompressed PCM format — the Mac-side equivalent of WAV, same size, same fidelity. Matching inputs take a fast, lossless path; mismatched ones have to be reconciled to a common format, which is slower and costs one encode.
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.
Will Merge AIFF lower the quality of my AIFF audio files?
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No. Lossless audio is edited sample-exactly, so what comes back decodes bit-identically to what you would get doing the same edit in a desktop editor. You can repeat the cycle as many times as you like without accumulating any loss at all.
Are bit depth and sample rate preserved?
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Yes, unless you change them deliberately. A 24-bit/96 kHz source stays 24-bit/96 kHz — nothing is silently downsampled to 16/44.1, which is the failure mode that makes a master unusable.
Does Merge AIFF cost anything?
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No. Merge AIFF is free without an account, and nothing is added to the audio. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.
What can I upload to Merge AIFF?
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WAV, FLAC and AIFF, at any bit depth and sample rate up to and including 24-bit/192 kHz. Lossy files work in the same batch if you are mixing sources.
Why does a PDF site host Merge AIFF?
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PDF.to exists because PDF is where documents go to be shared and the worst place to keep them while they are still being worked on, so nearly every job here is about getting something into or out of that state deliberately. A document rarely arrives in the state it needs to leave in: it is too big, in the wrong order, locked, or a scan with no text in it. Merge AIFF sits on the same upload and the same account as the conversions because those jobs turn up together.
What should I do with the result once Merge AIFF is finished?
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The converter on this site moves documents between PDF, Word, images, plain text and eBook formats in either direction, so whatever comes out of a tool here has somewhere to go next without a second upload. Running that after Merge AIFF rather than before keeps the document structure intact through the step that is most likely to flatten it.
Is Merge AIFF here the same tool the sibling sites run?
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The engines are shared — the same document toolchain, the same workers, the same limits. What a PDF site adds is a view on when a file should stay a document and when it genuinely wants to become something else, which is the decision most tools quietly make for you. It also starts from one fact about the format this site is named after: a PDF is an object graph, not a page image, so text stays selectable and vectors stay sharp no matter what happens to the raster content inside it.
Do I need an account, and does anything get kept?
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No account is needed. Uploads and results are kept for about 24 hours, which leaves time to download the result, and are then deleted automatically; nobody reads, lists or indexes them. Several files in one job need a paid plan.
