512×512 is the size that hides inside a dozen upload forms: the PWA app icon, the Discord server icon, the Telegram sticker canvas, the avatar that every chat app crops from a square. This free tool is preset to exactly 512×512. Upload a logo, illustration or photo, fit it with Fill, or pad it with Fit on a transparent background, and download a PNG that every one of those forms accepts without a fight.
It all happens in your browser — nothing uploaded, no watermark, no sign-up. The 192×192, 256×256 and 1024×1024 presets cover the rest of the icon family from the same master image.
Everywhere 512×512 is the magic number
Progressive Web Apps ask for a 512×512 icon (plus a 192×192) in the manifest; without them the “install” prompt never appears. Discord recommends at least 512×512 for server icons. Telegram stickers are defined on a 512-pixel canvas — one side exactly 512, the other 512 or less, in PNG or WebP. Chat and community avatars (Slack workspaces, forums, gaming profiles) upload square and display small, and 512 is the size that stays crisp on retina displays without being wasteful. Favicons have grown up too: modern sites ship a 512 master and let browsers scale it. Even app-store and launcher asset pipelines start from a 512 or 1024 square. Learn this one size and half the internet’s upload forms stop arguing with you.
Fit on transparent: the icon-maker’s mode
Icons are rarely full-bleed photographs; they are marks on a background. That makes Fit the hero mode here: choose the transparent background, and your logo or character is centred whole inside the 512 square with clear space around it — precisely what an app icon or sticker needs. Padding matters: operating systems mask icons into circles, squircles and teardrops, and a mark that touches the edges gets its corners amputated by the mask. Leave roughly 10% breathing room — in Fit terms, resize a version slightly smaller than full-bleed. For stickers, transparency is not optional, so export PNG or WebP and check the preview’s corners are truly empty.
Fill for photos and avatars
When the 512 square is a photo — a server icon from a group picture, an avatar from a portrait — Fill centre-crops to the square with no distortion. If the crop amputates the subject, reposition the original first with the image cropper, or make the round version directly in the circle crop tool at 512 and skip a step. Either way the exported file is exactly 512×512, so the platform’s own resizer — often the worst cropper in the pipeline — has nothing left to decide.
Small file, sharp edges
At 512 pixels, format choice is visible. Logos, icons and illustrations have hard edges and flat colour: PNG keeps them knife-sharp and preserves transparency, and at this size the file stays small anyway. Photographic avatars can go JPG if a form rejects PNG, but most icon forms prefer PNG. Export from the largest, cleanest master you have; a 512 made from a 4000-pixel original will always beat a 512 rescued from a 128-pixel thumbnail.
Maskable icons and the safe zone
If the 512 is headed for a PWA or an Android launcher, design for the mask, not the square. Maskable icons are cropped by the system into circles and other shapes, and the standard expects your key content to live inside a central safe zone — a circle about 80% of the canvas. In practice: run your icon through Fit mode with the transparent background so the mark already sits small and centred, or design the mark at roughly 400×400 inside the 512 canvas. An icon designed edge-to-edge looks great in the upload preview and loses its corners on the home screen; an icon designed for the mask survives every shape the system throws at it.
Related tools
Circle Crop Image · Resize Image to 1080×1080 · Versión en español: Redimensionar a 512×512 · Online Image Resizer Tool.
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