Audio to Video

Plenty of places built for sharing do not take sound files on their own. YouTube's upload page lists only video formats in its supported file formats, and most social apps treat posts as photos or videos. A song, a podcast episode, a voice message or a recorded talk therefore has to travel as a video, even when there is nothing to watch.

This tool builds that video around your sound. The audio stays the main thing, and the picture is whatever suits it: the album cover, the podcast artwork, a set of photos from the event, or a waveform that moves with the sound. The result is an ordinary video file that plays in any player and uploads like any other clip.

The frame sizes above are the presets in Video size. Pick the one that matches where the video will appear; a wide frame posted to a vertical feed is shown small with large empty areas, and a vertical frame on a wide player gets bars at the sides. Same as the image uses the picture's own shape, which is handy when you have already prepared artwork at the right size.

Uploaded image is the default and the most common choice. With one picture, it stays on screen for the full length of the audio. With several, they play in order as a slideshow. Image fit decides what happens when the picture's shape differs from the frame: Contain shows the whole image with bars in the background color, Cover fills the frame and crops the edges, and Blurred fill places the whole image over a soft, enlarged copy of itself so there are no plain bars. Blurred fill looks good with square album covers in a wide or tall frame.

Waveform draws the sound itself and moves with it. Four styles are available: Bars and Spectrum react clearly to music, Line suits speech and podcasts, and Circle gives a centered, badge-like look. Waveform color and Background color set the two colors; a light waveform on a dark background reads well on phones. This option needs no image at all.

Plain color shows a single still color for the whole video. It makes the lightest file and is a reasonable choice when the platform only needs a video wrapper, for example to share a long voice recording with a few people.

Add several images together with one audio file and the tool turns them into a slideshow. Seconds per image sets how long each picture stays, between 1 and 60 seconds in half-second steps. Transition chooses what happens between pictures: a hard Cut, a soft Crossfade (the default) or a Slide.

Repeat images to fit audio decides how pictures and sound line up. When it is on, the slideshow starts over until the music ends, so a few photos can carry a long track. When it is off, the pictures are spread evenly over the length of the audio, so each one stays on screen longer. If you upload images without any audio, each is shown for the set number of seconds, which gives a silent slideshow.

A few habits make slideshows look better. Use pictures with the same orientation as the frame where you can, or keep Blurred fill on so mixed portrait and landscape shots look tidy. Put the strongest image first, since some platforms use the opening frame as a preview. And add a short Fade out at the end so the music and picture finish together instead of stopping abruptly.

Convert to offers MP4, MOV and WebM. MP4 is the right choice for uploading and sharing; YouTube's upload encoding guidance names MP4 as the recommended container. MOV fits Apple editing apps if you want to keep working on the video, and WebM suits pages on your own site.

The audio inside the video is encoded at the Audio bitrate you choose, from 128 to 320 kbps. The default of 192 kbps is clean for music, and platforms re-encode uploads anyway, so higher values mostly add size. A still image adds very little to the file, because the picture hardly changes; a waveform or a slideshow with transitions adds more, since the picture moves.

The audio file you start from can be MP3, M4A, WAV, OGG, Opus, AAC, FLAC, AIFF, WMA and several others, and images can be JPG, PNG, WebP, HEIC, GIF, BMP or AVIF. If the sound needs work first, Audio Converter can normalize its volume, and the common case of a single MP3 with a cover image has its own page at MP3 to MP4.

The picture is what people see for the whole length of the audio, so it is worth a minute of preparation. Start with the largest version you have. A small thumbnail stretched over a 1080-pixel frame looks soft on a phone and blurry on a TV, while a large image scaled down stays crisp. If your artwork exists only as a low-resolution file, Increase Image Size can enlarge it before you start.

Keep text away from the edges. With Cover, the sides or the top and bottom of the image are cropped to fill the frame, and a title near the border may be cut off. Contain and Blurred fill always show the whole picture, which makes them the safer choices for artwork with lettering.

Phone photos in HEIC format are accepted as they are, so there is no need to convert them first. Transparent PNG artwork is placed over the Background color, which is black by default; set it to a color that matches the artwork if the transparent parts should not look dark. And if the same audio needs to go out in several shapes, such as a wide version for a channel and a vertical one for a short teaser, run it twice with different Video size values rather than cropping one video later.