White out parts of a PDF with draggable boxes
Whiting out a PDF means drawing white boxes over content you want hidden, the digital equivalent of correction fluid; this tool lets you drag the boxes on a page preview and then export in one of two modes: vector boxes, where the covered text still exists underneath and tools can remove the boxes, or flatten-to-image, where pages become pictures and the covered content is destroyed. Everything runs in your browser with no upload.
How it works
Placing the boxes is the easy half. Each page is rendered by the pdf.js engine into a preview canvas, and you drag white rectangles wherever content should disappear — over a printed price, a wrong date, a stray annotation. The tool records each rectangle's position in preview pixels and converts it to PDF points, flipping the y-axis because PDF measures from the bottom-left corner. What happens at export is the half that matters, and the tool makes you choose between two modes with genuinely different consequences.
Vector mode uses pdf-lib to append a filled white rectangle operation to each affected page's content stream. PDF pages paint in order, so an opaque rectangle drawn last covers whatever sits beneath it — visually. Structurally, nothing is removed: the original text operators and images are still in the file, one drawing instruction below the box. The text remains selectable (drag-select across the box and paste, and the "hidden" words appear), searchable, and extractable, and any PDF editor can delete the rectangle to reveal everything. This mode is fast, keeps the file small and the surrounding text live, and is exactly right when the goal is cosmetic — cleaning up a form before printing, not concealing secrets.
Flatten mode exists for when the covered content must actually be gone. Each page is first rendered — with its white boxes painted in — to a canvas bitmap, and the output PDF is rebuilt from those bitmaps, one full-page image per page. The pixels under a box are white in the bitmap; the original text operators were never carried into the new file, so there is nothing underneath to recover by any means. The costs are the usual rasterization trade-offs: the whole document becomes non-selectable images, file size typically grows for text pages, and links and form fields disappear. That asymmetry is the honest summary: vector mode is reversible by design, flatten mode is irreversible by design — pick by whether the content underneath is merely untidy or actually sensitive. For sensitive material you may also prefer black-box redaction, which follows the conventional marking style and likewise removes the underlying text.
Illustrative example: reusing a supplier quote as a blank template
Illustrative scenario, not a recorded benchmark. File sizes, timings and results depend on the input and device. Try the reproducible samples.
An office manager has a well-formatted 2-page supplier quote (240 KB) and wants to reuse its layout for a price comparison, minus the original supplier's prices and contact details. She drags seven white boxes: five over the line-item prices, one over the totals block, one over the contact footer.
Exported in vector mode, the file is 242 KB — the boxes add about 2 KB of drawing operations — and the remaining text is still selectable, so she can copy item descriptions straight out of it. She also checks the failure case deliberately: selecting across a covered price and copying pastes the "hidden" number, confirming vector mode conceals nothing from anyone who looks. Because this file is going outside the company, she re-exports in flatten mode instead: the output grows to 610 KB as both pages become images, but the prices are now genuinely absent — text extraction returns nothing where the boxes sit, and no editor can peel the boxes off. Two exports, two minutes, and the right mode chosen for each audience.
White-out — frequently asked questions
How do I white out text in a PDF?
Open the PDF in the tool, drag white rectangles over the content you want covered, and export. Choose vector boxes for a fast, reversible cover-up, or flatten-to-image if the covered content must be unrecoverable.
Is text under a white-out box still in the PDF?
In vector mode, yes: the box is drawn on top and the original text remains underneath, selectable and extractable by any PDF tool. In flatten mode the page is re-rendered as an image with the box baked in, so the covered content is gone from the file.
Which white-out mode should I use, vector or flatten?
Use vector when hiding is cosmetic, such as tidying a form before printing, because it is fast, lossless, and undoable. Use flatten when the hidden information must not be recoverable, accepting that pages become images and text is no longer selectable.
Is whiting out a PDF the same as redacting it?
Only the flatten mode is comparable, because it actually destroys the covered content. Vector white-out is cosmetic and can be reversed by anyone with a PDF editor; for sensitive data, use flatten mode or a dedicated black-box redaction tool.
Does white-out work on scanned PDFs?
Yes, and it is a natural fit: a white box on a white scan background looks like nothing was ever there. On scans there is no hidden text layer to leak unless OCR was applied, but flatten mode is still the safer export for sensitive content.
Are my files uploaded when I white out a PDF online?
No. The preview, the box drawing, and both export modes run entirely in your browser using pdf.js and pdf-lib. The document never leaves your device.