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How to convert an MP3 to an MP4 with an image on Windows

By Nicholas Johnson, who makes Podwobble · 9 October 2026

The short answer: an MP3 has no picture, so “converting” it means making a video with a still image and your audio as the soundtrack. On Windows, the free route is Clipchamp, Microsoft’s own video editor: add the picture and the MP3, stretch the picture to the audio’s length, and export a 1080p MP4 with no watermark.

People search for an MP3 to MP4 converter when a site won’t take their audio. YouTube is the usual one. Its help page says it plainly: “You can’t upload audio files to create a YouTube video.” This guide covers three free ways to make that video on a Windows PC, starting with Microsoft’s own free editor. The third is Podwobble, the app I make, so read that part knowing who wrote it. On a Mac, see the Mac version of this guide. Facts about other tools come from their own pages, linked as I go, as they stood on 9 October 2026.

Can you convert an MP3 straight to an MP4?

Not in the way you convert a WAV to an MP3. An MP3 holds sound and nothing else, and a video needs a picture for every second it plays. So every tool that “converts” an MP3 to an MP4 is doing the same two things: holding one image on screen for the length of the audio, and saving the pair as a video file. Some hide that behind a single button and choose the picture for you. It is worth choosing it yourself.

What do you need before you start?

• The audio file. The finished episode, song or recording, as you want people to hear it.
• One picture, in the shape of the video. For YouTube that is 16:9, so make the image 1920 by 1080 pixels. For Reels, Shorts and TikTok it is 9:16, so 1080 by 1920. Square show art dropped into a wide video leaves bars down both sides, or gets cropped.

How do you do it with Clipchamp, Microsoft’s free editor?

Clipchamp is the video editor Microsoft makes for Windows, and it does this job for free with no watermark. Microsoft says it might already be installed on Windows 11; if it isn’t, or you’re on Windows 10, it is in the Microsoft Store. You sign in with a personal Microsoft account.

1. Open Clipchamp. Search for it in the Start menu, sign in and create a new video.
2. Set the shape. Click the size button above the preview and pick a ratio. Clipchamp offers seven, including 16:9, 9:16, 1:1 and 4:5.
3. Bring in the files. Open My media in the left sidebar and click Import media, or drag the MP3 and the picture into the panel. Clipchamp’s supported formats include MP3, WAV, M4A, Ogg and FLAC for audio, and JPEG and PNG for images.
4. Put both on the timeline. Drag the audio down first, then the picture above it. If the picture is shorter than the audio, select it and drag the green bar at its right-hand end along the timeline until it ends where the audio ends.
5. Export. Click Export at the top right and choose 1080p. The video saves to your computer, usually in the Downloads folder.

What comes out is an MP4 at 30fps. On a personal account 480p, 720p and 1080p are free and 4K needs a paid plan. Microsoft’s page on watermarks says Clipchamp doesn’t add one. The one thing that stops a free export is using premium stock or a premium feature, so stick to your own picture and audio.

Three things to know before you rely on it every week:

• Your audio isn’t uploaded for editing. Microsoft says that in the personal version media files don’t get uploaded to a server for processing, unless you turn on content backup or use a sharing option. Captions are the exception: autocaptions need the audio processed by Microsoft’s Azure Cognitive Services to write the captions.
• One project makes one shape. For a wide video and a vertical one, Microsoft’s advice is to make a copy of the project and change the copy’s ratio, then export each.
• It wants a fair amount of memory. Microsoft recommends at least 8 GB of RAM for Clipchamp, and 16 GB or more if you can.

What happened to the Video Editor in the Photos app?

Older guides tell you to open Video Editor from the Photos app. If you can’t find it there, Microsoft lists it in the Microsoft Store as part of Microsoft Photos Legacy, a free download described as the app for its legacy collections, albums and Video Editor. Clipchamp is the one Microsoft now calls the official Windows video editor.

How do you do it with one FFmpeg command?

If you don’t mind a command line, FFmpeg does the whole thing in one line with no editor, no account and no watermark. FFmpeg is free and open source. The project publishes source code only and links to ready-made Windows builds, including the ones from gyan.dev. That build is also in winget, so you can install it from a terminal:

winget install -e --id Gyan.FFmpeg

Close and reopen the terminal, go to the folder with your two files, and run:

ffmpeg -loop 1 -i cover.jpg -i episode.mp3 -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 192k -shortest episode.mp4

What the parts do:

• -loop 1 repeats the picture for as long as it is needed. In FFmpeg’s words: “If set to 1, loop over the input.”
• -shortest ends the video when the audio runs out. Without it the looping picture never stops and neither does FFmpeg.
• -c:v libx264 -pix_fmt yuv420p makes ordinary H.264 video, and -c:a aac -b:a 192k turns the MP3 into AAC audio, the usual pairing inside an MP4.

Use a picture that is already 1920 by 1080 (or 1080 by 1920 for vertical). The video takes the picture’s size, and this command needs the width and height to be even numbers.

This is the quickest route if you have fifty episodes to get through, because the same line works in a loop. It is also the plainest result: a still image and sound, the same as the Clipchamp steps above. FFmpeg can draw a moving waveform over the picture too; the command is in how to add a waveform to audio.

What if you want the picture to move?

A still image gets your audio accepted. It doesn’t give anyone scrolling past a reason to stop, because nothing on screen says there is sound. Two of the routes here can fix that.

In Clipchamp

Clipchamp has a free audio visualizer. It is an overlay in the content library that you drag onto the timeline above your picture and stretch to the length of the audio. You can switch it between bars and waves and change its colour, size and position. For one video on a PC that already has Clipchamp, this is a good answer and it costs nothing.

In Podwobble

Podwobble is a desktop app for this one job, on Windows and Mac. You drop the audio into Voices (MP3, WAV, M4A, FLAC, AIFF or Ogg) and give each host a photo, a name and a colour. In Look you pick a template: a ring around the photo that reacts to the voice, or one of four waveform styles, with your logo, text and a background image. Captions transcribes English on your own computer, so the audio isn’t sent anywhere. In Export you tick 16:9, 9:16, 4:5 and 1:1 and they all render in one go as H.264 MP4 at 30fps, for the whole file or the stretch between an in and an out point.

Its catches: the free version puts a small Podwobble mark in the bottom-right corner of every export, and Pro removes it. It needs 64-bit Windows 10 or 11 on an Intel or AMD processor, so not Windows on Arm. The installer isn’t code-signed yet, so Windows may ask you to confirm the first time; the support page has the steps, and the Windows announcement covers what to expect. And it is not a general converter. If all you want is a still image and sound with no mark, Clipchamp or FFmpeg is the better tool.

The three routes, side by side

There are also websites that take an MP3 and hand back an MP4. They suit a short file on a computer you can’t install anything on. Before you upload an hour-long episode, check the site’s file size limit and what picture it uses.

Which one should you pick?

• One file, and you just need YouTube to accept it. Clipchamp. It may be on your PC already.
• A back catalogue of episodes. FFmpeg, run over the folder. If the destination is YouTube, check first whether its RSS import would do it for you; my guide to turning a podcast into a YouTube video compares the two.
• A video every week, in more than one shape, with captions. Podwobble, with its small mark, or Clipchamp with the visualizer if you’d rather build each one yourself.

For more free options beyond Windows, including web tools and their limits, see the free ways to turn a podcast into a video.

Questions

Why won’t YouTube accept my MP3?

YouTube only takes video files. Its help page says you can’t upload audio files to create a video, so the audio has to be saved as a video with a picture first.

Does Clipchamp put a watermark on the video?

No. Microsoft says Clipchamp doesn’t add a watermark, and free personal accounts can export up to 1080p. If you’ve used premium stock or a premium feature, it asks you to upgrade or remove it before exporting.

What size should the image be?

The same shape as the video: 1920 by 1080 pixels for a 16:9 YouTube video, 1080 by 1920 for a vertical one, 1080 by 1080 for a square.

Can I convert an MP3 to an MP4 on Windows without uploading it?

Yes. FFmpeg and Podwobble work on files on your own PC, and Microsoft says the personal version of Clipchamp doesn’t upload media for processing unless you turn on backup or share from it. Its autocaptions are separate: they send the audio to Azure to be processed.

Written with the help of AI, from my notes on how Podwobble works. Facts are checked against the linked sources.