MJPEG to ICO Converter

MJPEG to ICO: What This Tutorial Covers

This tool takes one frame out of a Motion JPEG capture — a webcam recording, an IP or security-camera export, a capture-card clip — and writes it as a Windows .ico icon. The extraction is the straightforward part, because every MJPEG frame is already a complete, independent JPEG and comes out without the inter-frame smearing you can hit when grabbing from H.264 or HEVC. The part worth reading before you convert is the sizing, which does not behave the way most people expect from an icon tool: the preset list sets the icon's height, and the width follows your video's aspect ratio. A widescreen frame therefore produces a wide, non-square icon, and above a certain preset it produces one the ICO format cannot describe properly. The sections below cover how to stay inside that limit and what to do when you need a true square.

How to Convert MJPEG to ICO

1. Upload Your MJPEG File: Drag your .mjpeg or .mjpg clip onto the page, or click "Add Files" to browse. Several clips can be queued and an icon taken from each.
2. Choose the Frame Under Frame Selection: Specific Frame is preselected with Time (seconds) at 0, which grabs the opening frame; type a decimal value to pick any other moment. Multiple Screenshots samples the clip at a chosen capture rate if you would rather compare several candidates.
3. Pick a Height Under Preset Resolutions: The dropdown offers 256P, 192P, 180P, 128P, 64P, 48P, 32P, 24P and 16P. Each value is a height — width is derived from your source's aspect ratio — so for a 16:9 capture, 128P is the largest choice that keeps the icon inside what the ICO format can declare.
4. Convert and Download: Click Convert and save the .ico. Uploads travel over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours. No sign-up, no watermark.

Walk-through: The Preset Is a Height, Not a Box

This is the one thing that catches people out, so it is worth being explicit. When you select 256P, the converter scales your frame to 256 pixels tall and lets the width land wherever the source aspect ratio puts it. On a 1920×1080 capture that is 455 pixels wide.

That matters because of how the ICO container describes its contents. Each image in an icon file is catalogued by an ICONDIRENTRY structure, and in Microsoft's icon format documentation the bWidth and bHeight members are single BYTE fields. A byte cannot hold 455. Anything wider than 255 pixels cannot be catalogued correctly, which is why 256 is the ceiling everyone quotes for icon dimensions — and why a preset that looks safe on paper is not safe once the aspect ratio multiplies it.

The practical rules that fall out of this:

• 16:9 sources (most cameras, most screen captures): 128P is the largest usable preset. It yields roughly 228×128.
• 4:3 sources (older IP cameras, many machine-vision sensors): 180P is the largest comfortable choice at 240×180; 192P lands exactly on 256 wide, right at the edge.
• Any source: the smaller presets — 64P, 48P, 32P, 24P, 16P — are always safe, and are the sizes Windows actually asks for most often.
• You need a genuine square icon: you cannot get one here, because the width-, height- and percentage-based resolution controls do not render on this page. Take the route described under "When This Doesn't Work" instead.

Preset Height vs Resulting Icon Width

MJPEG Source vs ICO Output

Common Errors and How to Fix Them

• "The icon is stretched or has odd proportions" — The preset set the height and the width came from your video's aspect ratio, so a 16:9 frame produced a wide icon. Software that expects a square will letterbox or distort it. Use the PNG route below to crop a square first.
• "Windows or my IDE won't accept the .ico" — Most likely the icon is wider than 255 pixels, which the icon directory cannot describe. Re-run at 128P or smaller.
• "The icon looks muddy at small sizes" — A detailed video frame reduced to 32 or 16 pixels tall loses nearly everything. Pick a frame with a single bold, high-contrast, centred subject; fine detail and busy backgrounds never survive the downscale.
• "I got several files instead of one" — Multiple Screenshots was selected under Frame Selection. Switch back to Specific Frame and set one timestamp.
• "Nothing comes back at my timestamp" — The value is past the end of the clip. Raw MJPEG carries no duration metadata, so players often mis-report a capture's length; try a lower number.
• "I wanted several sizes in one file" — Each conversion writes a single image. Run it once per size you need, or build a multi-size icon from a squared PNG with a dedicated icon editor.

When This Doesn't Work

If you need a proper square icon — which is what Windows shortcuts, taskbar pins and favicons really want — this page cannot produce one on its own, because the only resolution control it exposes is the preset height. The reliable route is three steps: extract the frame with MJPEG to PNG, square it up with crop PNG so the subject sits in a 1:1 frame, then run PNG to ICO on the result. That also gives you the chance to add a transparent background, which a video frame can never supply, and to compose the artwork so it stays legible once it is 32 pixels tall. It is more clicks, but it is the difference between an icon that happens to be a video still and one that works as an icon.

Frequently Asked Questions

Why isn't my icon square?

Because the preset list on this page sets height only, and the converter derives the width from your source's aspect ratio. A 1280×720 frame at 128P becomes roughly 228×128, not 128×128. The controls that would let you force exact dimensions — width, height and percentage inputs — do not render on the ICO target, so there is no way to square the image at this stage. Crop the frame to 1:1 before it reaches the icon step, using the PNG route described above.

What is the largest icon size I can actually use?

Not the largest number in the dropdown. The icon directory stores each image's width and height as single bytes, so 255 pixels is the hard ceiling for what can be catalogued (256 is addressable only by convention). Since the preset controls height and the width follows the aspect ratio, a 16:9 frame at 256P works out around 455 pixels wide and cannot be described correctly. For widescreen sources, treat 128P as the practical maximum; for 4:3 sources, 180P.

Which size should I choose for a website favicon?

Browsers commonly request 16 and 32 pixel icons for tabs and bookmarks, and Windows uses 48 for shortcuts and larger sizes for taskbar pins. For a favicon specifically, 32P is the sensible single choice with 16P as the low-DPI fallback. Bear in mind that a favicon really should be square, so the PNG-crop route is worth the extra two steps if the icon is going onto a live site rather than into a quick internal tool.

Why grab an icon from an MJPEG rather than taking a screenshot?

Two reasons. First, precision: addressing a frame by timestamp is repeatable, whereas a manual screenshot captures whatever the player happened to be displaying and is tied to your screen's scaling. Second, fidelity: every MJPEG frame is a complete, self-contained JPEG, so it decodes exactly as recorded — there is no inter-frame reconstruction that might introduce blocking, which is the risk when you pull a frame from H.264 footage between keyframes.

Does the icon keep any transparency from the video?

No, and it cannot. JPEG has no alpha channel, so every frame in a Motion JPEG stream is fully opaque and there is simply nothing transparent to carry across — the icon's background will be whatever the camera was pointed at. The ICO format itself handles 8-bit alpha perfectly well, but that has to come from a source that already has it. Start from a transparent PNG via PNG to ICO if you need a cut-out subject.

Can I compare a few frames before committing to one?

Yes. Set Frame Selection to Multiple Screenshots and choose a capture rate, which runs from one frame every 0.1 seconds up to one every 10 seconds. That returns a set of stills sampled across the clip so you can pick the sharpest, best-composed candidate, then re-run with Specific Frame at that timestamp. It is the practical approach when the subject is moving, since a small icon is unforgiving of motion blur.

Does the length of my recording affect how long this takes?

Barely. Only the frame you asked for is decoded, so a two-hour surveillance export converts about as fast as a ten-second clip once it has finished uploading. The real cost with a long capture is transferring it to our servers in the first place — the file is processed server-side, so upload time, not clip length, is what you will be waiting on. Trimming the recording beforehand is the quickest way to cut that down.

What happens to my video after the conversion?

It is uploaded over an encrypted connection, decoded on our servers to extract the frame you selected, and both the upload and the resulting icon are deleted automatically after a few hours. Nothing is shared or made public, no account is required, and no watermark is applied to the output. If you would rather keep the frame as a full-size, editable image instead of an icon, MJPEG to PNG preserves the original frame dimensions and gives you something to work from.