ID card & document cropper

Crop & straighten any ID document

Drop a photo of a card or document. We detect the edges, let you fine-tune the corners, and warp it into a flat, scanner-clean crop — entirely in your browser.

Drop a photo of an ID or document
JPG · PNG · WebP — auto edge detection, runs entirely in your browser
PNG · JPG · WEBP · max 25.0 MB
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The complete guide to cropping ID documents online

Turn a phone photo of any ID into a clean, straight scan

Scanning a small document is surprisingly awkward. Flatbed scanners are slow and rarely to hand, and most scanner apps either over-process the image or leave you with a crooked, off-angle crop. The OpusImg ID card cropper takes the opposite approach: photograph the document however is convenient, and let the tool find the edges, remove everything around it, and straighten the result into a flat rectangle.

Under the hood it does two things. First it detects the document quadrilateral — the four corners of the card against the background behind it. Then it applies a perspective transform that maps those four corners onto a perfect rectangle, undoing the keystone distortion you always get when you shoot a document at an angle. The output looks like it came off a scanner, but you took it with a phone in a couple of seconds.

Automatic edge detection, with manual control where it counts

When you drop a photo, the tool analyses it and proposes a four-corner crop. It works by separating the document from the surface behind it — a bright card on a dark desk, or a dark card on a light table — and finding the extreme corners of that region. For most well-lit photos against a contrasting background, the proposed corners land right on the document.

Detection is only ever a starting point, though. The four corners are shown as draggable handles, and the perspective correction uses exactly where you place them. So if the photo has a busy background, a fold, or low contrast, you simply nudge each handle onto the real corner. Keyboard arrows give pixel-level precision, and a reset button snaps the handles back to the detected position if you want to start over.

Standard sizes for IDs, cards, and scanned pages

Different documents want different proportions. Most national ID cards and credit cards follow the ISO/IEC 7810 ID-1 standard, better known as CR80 — 85.6 by 54 millimetres, an aspect ratio of about 1.585. Choosing the CR80 preset forces the crop to that exact ratio so the card isn't stretched or squashed. There are also A4 and US Letter presets for full pages and forms, and a square option.

If you'd rather keep the document's own measured proportions — useful for non-standard sizes or when you've cropped tightly to the printed area — the Auto option preserves whatever shape your four corners describe. Either way the tool renders at the resolution implied by your corners, so a high-megapixel phone photo produces a high-resolution crop.

Built for privacy: nothing leaves your device

Identity documents are exactly the kind of file you should be careful about uploading. The ID card cropper is designed so you never have to. Decoding the photo, detecting the edges, warping the perspective, and encoding the final PNG all happen locally in your browser using the canvas API. No bytes are sent to a server, there's nothing to delete afterwards, and the tool even works offline once the page has loaded.

That privacy-first design is the same model OpusImg uses for every client-side tool — compression, conversion, resizing — and it's especially important here. Whether you're cropping a passport for a visa application, a licence for a rental, or an insurance card for a claim, the document stays on your machine.

From a clean crop to a finished document

A straightened crop is often just the first step. Once you've downloaded the PNG you can open it in the OpusImg editor to redact sensitive numbers, add a 'for verification only' watermark, or annotate fields. If you have both sides of a card, or several pages of a form, the Image to PDF tool stitches them into a single document ready to email or upload.

For documents that are creased, shadowed, or photographed in poor light, pair the cropper with the scan cleanup tool, which deshadows, dewarps, and sharpens scanned pages with an AI pipeline. Together they cover the whole journey from a quick phone snapshot to a polished, submission-ready document.

Keep going

Frequently asked questions

How does the ID card cropper work?

Drop a photo of an ID card, licence, or document. The tool automatically detects the document's four corners, shows them as draggable handles so you can fine-tune the fit, then applies a perspective correction that warps the angled document into a flat, straight-on rectangle. The result is a clean crop with the surroundings removed and any keystone distortion fixed.

What is perspective correction?

When you photograph a card or document at an angle, it looks like a trapezoid rather than a rectangle — the far edge appears shorter than the near edge. Perspective correction (a homography warp) remaps the four corners back to a true rectangle, so the document looks like it was scanned flat-on, even though the photo was taken at an angle.

Do I need a scanner?

No. A phone photo is enough. The whole point of the tool is to turn a quick handheld snapshot into a scanner-quality crop — it detects the edges, removes the desk or table behind the card, and straightens the result. You don't need a flatbed scanner or a special app.

Is my document uploaded to a server?

No. Edge detection, the corner adjustment, and the perspective warp all run entirely in your browser using the device's own canvas. Your ID or document never leaves your computer or phone, which matters a lot for sensitive documents like passports, licences, and national ID cards.

What output sizes can I choose?

Auto keeps the document's detected shape. You can also force a standard aspect ratio: the CR80 ID-card size (85.6×54mm — used by most credit cards and national IDs), A4 or US Letter for scanned forms and pages, or a square. The tool keeps the longer measured edge and derives the other side from the ratio so the crop is exactly compliant.

The auto-detect didn't find my document — what now?

Auto-detection works best when the document contrasts with the surface behind it (a light card on a dark desk, or vice versa). On busy or low-contrast backgrounds it may miss. When that happens, just drag the four corner handles onto the actual corners of your document — the perspective correction uses your handles, so a manual adjustment gives a perfect result.

Can I crop a passport or driver's licence?

Yes. The tool is ideal for passports, driver's licences, national ID cards, residence permits, insurance cards, and business cards — anything rectangular. Because everything runs locally, it's safe to use on identity documents you wouldn't want to upload to a third-party website.

Why is my free crop watermarked?

The ID card cropper is a Pro tool. Free accounts can try it with a faint watermark baked into the result so you can see the quality before upgrading. A Pro plan removes the watermark, gives you unlimited crops, and exports at full resolution.

What file formats are supported?

You can drop JPG, PNG, or WebP photos, and the crop is exported as a PNG. PNG is lossless, so text on the document stays crisp and there's no compression blur around fine print and signatures.

Can I use the cropped document in the editor?

Yes. Download the PNG and drop it into the OpusImg editor to annotate, redact sensitive fields, or combine it with other pages. For multi-page documents you can also turn several crops into a single PDF with the Image to PDF tool.