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 MKV file.
Merge MKV FAQ
Does it matter if the inputs are different formats?
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It does. MKV imposes no codec restrictions and carries unlimited audio, subtitle and chapter tracks, which is why rips use it and TVs often refuse it. 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 MKV when merging?
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Yes — MKV places no restriction on what is inside it, so an edit has to carry every audio, subtitle and chapter track across rather than assuming one of each. That is worth checking when the inputs did not all come from the same source.
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.
Can I run Merge MKV on several MKV videos at once?
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Yes. Uploads queue in parallel, which matters more here than anywhere else because video jobs are minutes rather than seconds. Free accounts run one file at a time; a pass lifts that.
Does Merge MKV cost anything?
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No. Merge MKV is free without an account, and the output has no watermark, corner logo or intro card. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.
Is there a file size limit on Merge MKV?
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Yes: free accounts process video up to 40 MB per file, by far the most generous cap on the site; ffmpeg with x264, x265 and libvpx does the work, which is the same toolchain behind most desktop video software. Video is the one family where the cap is high enough that upload time, not the limit, is what you will actually notice.
Why does a PNG site host Merge MKV?
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PNG.to is built around the format you use when you cannot afford to lose a pixel: lossless, alpha-capable, and the correct answer for screenshots, logos, line art and anything with hard edges. Image work is rarely one step: people arrive to change a format and leave needing the picture a different size, a different weight or a different shape. Running Merge MKV on the same upload pipeline, the same size caps and the same account is the whole reason it is here rather than on a fourth tab.
What should I do with the result once Merge MKV is finished?
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The converter on this site moves images to and from PNG, JPG, WebP, GIF and SVG — which is the step where the decision about transparency actually gets made. That is the step most people actually came for, and doing it after Merge MKV rather than before it means the conversion works from the file you finally settled on.
Is Merge MKV here the same tool the sibling sites run?
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The engines are shared — the same libraries, the same workers, the same limits. What differs is the advice, and the advice here starts from one fact about the format this site is named after: there is no quality slider to get wrong — a PNG round-trips bit-exactly, so the only thing edits cost you is file size. A PNG site is opinionated about where PNG is the right destination and where it is not, and that judgement is worth more than the button.
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.
