Scan pictures and documents to PDF, free

Using a phone camera as a document scanner

A phone camera photographs paper; a scanner app makes that photograph behave like a scan. The difference is not the sensor — modern phones out-resolve a flatbed for A4 text — it is geometry and light. A camera held by hand shoots the page at a slight angle under uneven room light, so the raw photo has keystone distortion, a color cast and often a shadow where your arm crossed the lamp.

LensUp is the second half of that pipeline in a browser tab: it takes the photo you already captured with the camera and applies the scanner half — crop, perspective correction, a scan-style filter and PDF assembly. Nothing is installed and the photo is processed on your device, which is also why it works the same on a phone, a tablet and a laptop. That is all a phone needs to scan to PDF: the camera captures the page, and the browser does the scanner half.

Two habits improve every scan before software touches it. Shoot from directly above the page center rather than from a seated angle, and put the page near a window or lamp with your body on the opposite side, so your own shadow falls away from the paper instead of across it.

Prefer to shoot each page live? Try the online cam scanner.

A4, US Letter, or the photo’s own size

The export offers three page geometries. A4 is the international default and what most government, university and office workflows expect. US Letter is the North American equivalent — slightly wider and shorter. “Original” keeps each photo’s own pixel dimensions instead of placing it on a standard page, which suits images that are not paper at all, such as whiteboards or receipts you only need to read.

When a photo is placed on A4 or Letter, it is fitted inside the page with its proportions intact — nothing is stretched. A tall receipt on an A4 page therefore shows margins at the sides; that is correct behavior, not an error, and it is what makes the PDF print at a sensible size.

Scanning a stack of receipts? Scan receipts to PDF

Which files can go in

The importer accepts the formats phones and messengers actually produce: JPG, PNG and WebP, Apple’s HEIC and HEIF, plus TIFF, AVIF, BMP and GIF. iPhone users do not need to change the camera’s HEIC setting first — the conversion happens locally during import. An existing PDF can also be added, and its pages join the queue as images.

Multiple photos become one document. Add the pages in any order, then drag them into the right sequence before export; the PDF follows the order shown on screen, not the order of capture.

To scan paper to PDF without a scanner, photograph each sheet flat in even light, add the photos here and export. Each photo becomes one page when you scan to PDF, in the order shown on screen.

What a scanned PDF is — and when you need something else

The exported file contains page images, exactly like the output of an office scanner. Text in it is readable to a person but not selectable, and an existing PDF that is imported is rasterized, so live form fields, clickable links and selectable text from the source do not survive. For submitting evidence of a paper document that is normally what portals expect.

If the receiving side needs live, selectable text — a screen reader, copy-and-paste, a text archive — a picture of the page is the wrong deliverable no matter how cleanly it is scanned, and you should send the original digital file instead. Knowing which of the two the destination wants saves a rejected upload.