Scan Documents to PDF Online Free

CocoPDF Scanner turns your phone or webcam into a portable document scanner. Open the tool, point your camera at any paper document, whether receipts, contracts, notes, ID cards or forms, and capture it. The scanner automatically detects the document edges, straightens the perspective, and applies a scan-style filter so the result looks like it came from a real flatbed scanner.

All image processing runs locally in your browser using WebAssembly. Your photos are never uploaded until you tap "Convert to PDF" at the end. You can capture multiple pages, reorder them, delete the bad ones, and re-shoot any page that didn't come out right. When you're happy, the pages are merged into a single PDF and downloaded instantly.

No signup, no watermarks, no app install. Files are deleted from our server within one hour. Works on iPhone, Android, Windows, Mac, and Linux, anywhere with a modern browser.

The reason a captured page looks like a scan rather than a photo comes down to two steps that run automatically. Edge detection locates the four corners of the sheet against whatever it is resting on, and perspective correction then warps the image so those corners map to the corners of a rectangle. That second step is doing more work than it appears: text that was compressed at the far side of the frame, because that part of the page sat further from the lens, gets stretched back to its proper proportions, which is why a corrected capture reads evenly instead of tightening toward one edge.

Both of those steps run on your own device using WebAssembly, and nothing is transmitted while you are capturing or adjusting. That matters more than it might sound, because the documents people scan are exactly the ones they would rather not upload speculatively: passports, bank statements, medical letters, signed contracts. Only the finished pages are sent, at the moment you convert, and they are deleted from the server within an hour.

Lighting causes more disappointing captures than anything else. A lamp directly overhead produces a glare spot on glossy paper, and a window on one side produces a visible gradient across the sheet. Indirect daylight is the easiest condition to work in, and if you only have a desk lamp, aiming it at a wall and using the bounced light works far better than pointing it at the document. Avoid casting your own shadow across the page, which is easy to do when leaning over it.

Edge detection needs something to detect, so give it a clear boundary. Place the page on a contrasting surface, such as white paper on a dark desk, and leave a margin of background visible on all four sides rather than filling the frame edge to edge. A folded letter or a page curling out of a binder defeats the detector because the edges are no longer straight lines, so flatten the sheet first. If the automatic corners land slightly off, dragging them into place by hand takes a couple of seconds and is worth doing before you continue.

The filter is the biggest single influence on file size. Black and white stores roughly one bit per pixel, so a text page can end up a small fraction of the size of the same page in colour, and it also produces the cleanest look for ordinary printed documents. The caution is that it decides for every pixel whether it is black or white with nothing in between, so faint pencil, light highlighter, and thin signature ink can disappear entirely. When anything on the page is faint and matters, use grayscale instead, and reserve colour for pages where the colour itself carries meaning.

Once you have a finished PDF, it is still a set of images rather than text, so it cannot be searched or converted to Word as it stands. Running it through the OCR PDF tool adds a searchable layer while leaving the pages looking identical. Do that before compressing rather than after, because OCR reads the page image to identify characters and needs the full detail to do it accurately. Compressing afterwards is safe, since the text layer is stored separately and survives untouched.