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 PDF file.
Merge PDF FAQ
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.
Does it matter if the inputs are different formats?
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It does. PDF fixes the page: fonts, vectors, raster images and text coordinates are frozen so every reader sees identical layout. 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 PDF when merging?
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Yes — 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. That is worth checking when the inputs did not all come from the same source.
Will Merge PDF lower the quality of my PDF documents?
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Text and vector artwork are objects rather than pixels, so they stay perfectly sharp at any zoom no matter what happens. Only the embedded raster images can degrade, and only if the operation you chose resamples them.
Can I run Merge PDF on several PDF documents at once?
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Yes — upload the set and they process in parallel under one set of settings, which is the point of doing a document workflow here rather than clicking through a desktop reader.
Do bookmarks, links and form fields survive?
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Outlines, internal links and annotations are preserved wherever the operation allows it. Digital signatures are the exception: any change to the file necessarily invalidates a signature, because that is precisely what a signature is for.
Does Merge PDF cost anything?
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No. Merge PDF is free without an account, and nothing is added to the document. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.
Why does a WebM site host Merge PDF?
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WEBM.to is built around the container the open web actually chose — VP9 or AV1 with Opus audio, decoded natively by every modern browser and needing no plugin, licence or player. Video is the case where extra round trips hurt most — the files are large and every upload costs real minutes. Running Merge PDF on the same pipeline as the conversions means one upload covers the whole job instead of one upload per tool.
What should I do with the result once Merge PDF is finished?
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The converter on this site moves video between WebM, MP4, MKV, MOV and the rest, or pulls the soundtrack out entirely, without another upload. Sequencing it that way matters more for video than anywhere else: each re-encode is another generation, so the fewer of them stand between the source and the file you publish, the better it looks.
Is Merge PDF here the same tool the sibling sites run?
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The engines are shared — the same ffmpeg build with x264, x265 and libvpx, the same workers, the same limits. What a WebM site adds is a view on containers and codecs: which combinations play everywhere, which need a re-encode and which can simply be copied across. It also starts from one fact about the format this site is named after: WebM is VP9 or AV1 with Opus audio, which browsers decode natively but which most desktop editors still transcode on import.
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.
