Step 1: Upload your AMR files using the button above or by drag and drop.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Download your converted MP4 files.
AMR to MP4 Conversion FAQ
How do I turn a AMR audio file into a MP4 video?
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PDF.to wraps your AMR audio into a MP4 video with a static cover image (or a generated waveform) as the visual track. Upload the AMR, optionally drop in a cover image, and download the finished MP4.
Why would I convert AMR audio to a MP4 video?
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A MP4 video plays everywhere a raw AMR sometimes will not — most notably on video-only platforms and social feeds that require a video container. It is the standard way to publish a podcast, song, or mix as a shareable MP4.
What plays in the picture of the MP4?
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By default PDF.to shows a single still cover image for the full duration. You can upload your own artwork, or let the converter render an animated waveform that moves with the AMR audio.
Will the audio quality of my AMR change in the MP4?
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The AMR stream is re-encoded into the MP4 container at a high audio bitrate (192 kbps AAC by default), so it stays effectively transparent for music and speech. Lossless AMR sources are not upsampled.
What resolution is the MP4 video?
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The MP4 matches the cover image you supply, defaulting to 1280x720. Because the picture is static, a higher resolution adds almost nothing to the file size — the bulk of a MP4 made from AMR is the audio.
Can I set a custom thumbnail or cover for the MP4?
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Yes. Upload any JPG or PNG and PDF.to centers it on a solid background for the whole MP4. This is how you give a AMR track a branded video thumbnail.
Does the MP4 keep the title and artist tags from my AMR?
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Where the MP4 container supports metadata, title and artist tags from the AMR are carried over. The cover artwork embedded in the AMR is also used automatically if you do not supply your own.
Can I batch-convert many AMR files to MP4?
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Yes. Drop a folder of AMR files and each becomes its own MP4 video; all of them are zipped for a single download.
Is the AMR to MP4 conversion free?
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Yes for files under 100 MB. PRO unlocks larger AMR uploads (up to 5 GB), longer durations, and parallel jobs.
How long can the AMR be?
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Full-length albums and multi-hour AMR recordings convert fine. Because the picture is static, even a long MP4 stays modest in size relative to a filmed video of the same length.
Will the MP4 play on YouTube, Instagram, and TikTok?
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Yes. PDF.to encodes the MP4 with a widely supported codec and pixel format, so the resulting video uploads cleanly to the major platforms that reject bare AMR audio.
Are my AMR files private during conversion?
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Uploads are encrypted in transit, the conversion runs in an isolated worker, and both the AMR and the rendered MP4 are deleted automatically a short time after you download.