How to peel a background in this tab

Peel is a short sequence, not a cloud job. The photo is decoded here, a small net draws a mask, you download a PNG. Below is the order that actually works on a laptop and on iPhone Safari, including the two failures people hit on day one: HEIC from Camera Roll, and judging the mask against a checkerboard they then screenshot.

1. Shoot or pick a still that has a subject

U²-NetP looks for a salient object. A product on a kitchen table, a person standing a step in front of a wall, a bag on asphalt — those work. A landscape with no foreground object, a collage of five items, or a screenshot of a screenshot will produce a mushy matte. Light the subject harder than the backdrop if you can. Avoid white-on-white unless you are ready to recrop.

File types Peel opens: JPEG, PNG, WebP, under 15 MB. GIF, SVG, PDF and video are out. iPhone photos saved as HEIC often arrive as a type this decoder rejects. Convert them to JPEG first (any HEIC converter that runs on-device is fine), then drop the JPEG. On iOS, Peel also downscales the long edge to 2048 px before inference so WebKit does not kill the canvas.

2. Open Peel and wait out the first download

The first visit fetches two static files from this origin: the 4.7 MB u2netp.onnx weights and the onnxruntime-web WASM engine. That is not your photo leaving the machine. A progress bar reports the model. Cache Storage keeps both files, so the second peel on the same browser is much closer to instant. If you are on a metered mobile radio, do the first load on Wi-Fi.

3. Drop the file, then press Peel

Use the drop zone or the file picker. The image should appear in the original pane. If you see an error about HEIC, empty files or an unsupported type, stop — converting is faster than retrying the same blob. The Peel control stays disabled until a bitmap is in memory and the model reports ready. Tap targets are at least 44 px so the button is usable with a thumb.

Inference runs in a Worker. The main thread stays free enough to show a spinner. Typical laptop time after the model is warm is a couple of seconds. A large 12 MP still on an older phone can take longer and can still fail if the GPU is already full; shrink the JPEG and try once more.

4. Read the mask on the checkerboard

Switch the preview to the cutout. Holes in the subject mean the threshold is too hungry or the net missed a low-contrast limb. Chunks of sofa stuck to a sleeve mean the opposite. Threshold (default 50) is the hard cut of the saliency map. Feather 0 / 1 / 2 px blurs that cut so you do not get a jagged halo. One pixel of feather is the usual listing thumbnail. Zero is better on hard graphic logos. Two is a last resort on hair.

The checkerboard is CSS. It is not in the file. Do not screenshot it and upload that PNG to a shop. If you need white, switch to Solid and keep #FFFFFF, then download. That path is documented on white background. If you need the cutout on a real photograph, use photo backdrop — two files, cover-crop, not a hex. If you need alpha, stay on Transparent — transparent PNG notes.

5. Download, then look at the file in another app

Download writes a PNG from the canvas. Open it in Preview, Photos, or your design tool. Edges that looked fine on a 390 px phone will show matte errors at 100% zoom; that is the 320 px net, not a bug in the PNG writer. For a storefront card it is often enough. For a print-pack hero, it is a sketch.

iOS Share uses the system sheet when the browser allows file shares. If Share is missing, use Download. Peel does not email the file to us. Closing the tab drops the bitmaps from memory.

6. What to do when it looks wrong

Recrop so the subject is larger. Reshoot against a darker or simpler wall. Convert HEIC. Lower resolution if the tab crashed. Read limits before you spend an hour on a wine glass. Catalogue and headshot specifics are on product photos and portraits. After Download: save to Files not Photos on iPhone, do not photo-send a transparent PNG on WhatsApp, and do not feed alpha into a listing well — marketplace.

Peel will not strip a watermark, will not inpaint a logo, and will not queue 200 SKUs. Those are different tools, and some of them are not allowed on this site.