MOS to AVIF Converter

Convert MOS RAW to AVIF

Leaf MOS files are enormous, and almost nothing outside a photo editor will open one. This converter develops the RAW — demosaic plus a standard tone curve — and re-encodes the result as AVIF, the AV1-based still format that gives you the smallest modern web file at a given visual quality. It is the right target when a medium-format capture has to live on a web page, in a portfolio grid, or in an email, and the wrong target when someone downstream needs to edit it.

How to Convert MOS to AVIF

1. Upload Your MOS Files: Drag the captures onto the page or click "+ Add Files". Queue as many as you like; every file in the job is converted with the same settings and downloaded individually or as a ZIP.
2. Pick a Quality Preset: Quality Preset starts on Very High (Recommended) and runs Highest, Very High, High, Medium, Low, Very Low, Lowest. Very High is the sensible default for portfolio work; Medium is usually still clean enough for a thumbnail grid.
3. Set Image resolution or a Specific file size: Image resolution starts on Keep original, which for a medium-format capture means an image far larger than any web slot — switch to Preset Resolutions (which sets the height and lets width follow the source aspect ratio), Width (Keep aspect ratio), or Width x Height. Alternatively choose Specific file size, type a target, and leave Auto Scale on so dimensions can drop rather than quality collapsing.
4. Convert and Download: Click Convert and save the AVIF. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

AVIF vs the Other Export Targets for a Leaf Capture

AVIF at a Glance

Frequently Asked Questions

Does the AVIF keep my RAW's editing latitude?

No, and no rendered format would. A MOS holds undemosaiced sensor data at high bit depth; converting it produces a finished picture, which is the point of the conversion but also the end of the highlight-recovery and white-balance freedom you had. Treat the AVIF as a delivery file and keep the MOS originals as your masters. If you need an editable render instead, export from your RAW editor with your own settings applied.

Does the converter apply my Capture One or Leaf back adjustments?

No. The RAW is demosaiced and given a standard tone curve so it can be displayed — genuine RAW development, but not your development. Any white balance, curve, lens profile or retouching stored in your editor's sidecar files is not read here, so an AVIF made from the RAW will not match a graded export. When the look matters, render finished images in your editor first and convert those.

Which browsers and apps can open an AVIF?

About 95% of browser users globally: Chrome 85 and newer, Firefox 93+, Safari 16.4+ (16.1 had partial support), and Edge 121+. Desktop support outside browsers is more uneven than WebP's — some older photo viewers and layout tools still refuse AVIF. If your recipient is a client rather than a website, MOS to JPG is the safer hand-off.

How do I hit an exact file size?

Switch File Compression to Specific file size, type the number, and pick Bytes, Kilobytes, or Megabytes. Leave Auto Scale enabled: it allows the pixel dimensions to come down as well as the quality, which is almost always the better trade for a huge medium-format frame. Without it, hitting a small target at full resolution means the encoder has to destroy detail to get there.

How do I downscale a 100-megapixel capture sensibly?

Use Preset Resolutions, which sets the output height and lets the width follow your source aspect ratio — important with medium-format sensors, which are rarely 3:2 or 16:9. For a fixed layout slot, use Width x Height instead and accept whatever cropping or letterboxing your CSS applies. Downscaling first also speeds the encode up considerably, since AV1 intra coding is compute-heavy.

Is there a lossless AVIF option here?

Not on this page. The AVIF specification allows lossless AV1 coding, but the controls exposed for this conversion are the quality presets, a target file size, and resolution — Highest is the top of the quality scale rather than a guaranteed mathematically lossless mode. If you need a genuinely lossless render, use MOS to PNG with the Quality Preset set to Highest, which is the true-colour lossless path.

Does AVIF support transparency, and will my capture have any?

The format does — the specification defines alpha through auxiliary AV1 image items. Your MOS does not: a RAW file holds sensor data with no alpha channel, so the AVIF will be fully opaque. Transparency only enters the picture if you mask a capture in an editor first and convert the masked export.

Why does converting a single file take longer than a JPEG would?

Because AV1 intra coding does far more work per pixel than a JPEG encoder, and a medium-format capture hands it a lot of pixels. That extra effort is exactly where the file-size advantage comes from. Setting a resolution before converting is the fastest fix; a 2000-pixel-wide web image encodes very quickly compared with an untouched full-resolution frame.

Should I deliver AVIF or WebP?

AVIF for pages where weight is the deciding factor and the audience is on current browsers. WebP when you want the broadest modern coverage with less risk — its browser support is a little higher and desktop tool support noticeably better. Many sites serve AVIF first with a WebP or JPEG fallback, which you can build by converting the same MOS twice.

What happens to my captures after the conversion?

They are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public. Every file in a batch is developed and re-encoded with the settings you chose, so the same capture with the same preset produces the same output each time.