Flatten PDF online

What Flatten PDF does

Flattening turns interactive or editable parts of a PDF into fixed page content. People flatten a filled-in form before sending it, so the answers cannot be changed by accident and look the same in every viewer, printer and upload system.

Flatten PDF has two modes. Form fields uses pdf-lib to draw the values of the form fields into the pages and then remove the fields; the rest of the document stays as it is. Whole page to image renders every page with pdf.js and replaces it with a JPEG image of that page, which removes all text and structure.

How to use Flatten PDF

1. Drop your PDF files into the box.
2. Set the options for flatten pdf.
3. Click Apply. The PDF is processed on your device.
4. Download the new PDF.

When to use Flatten PDF

• Lock the answers in a completed job application or tax form before uploading it to a portal that may display fields incorrectly.
• Flatten a signed contract that contains form fields, so the filled-in names, dates and amounts can no longer be edited as fields.
• Make sure a print shop prints exactly what you see by turning every page, including comments and form values, into an image.
• Turn pages into images after using Whiteout, so the covered text is really gone and cannot be copied or found by search.

Settings explained

Form fields

The default. Writes the current value of each form field, including text, checkboxes and dropdowns, into the page and removes the fields. Text stays selectable and the file stays small. Comments and other annotations are not changed.

Whole page to image

Renders every page as a JPEG image at quality 90 and builds a new PDF from those images at the original page size. Everything visible is kept, but text can no longer be selected and links stop working.

Resolution

Shown for Whole page to image. 150 DPI, the default, is clear on screen and in normal prints. Choose 200 or 300 DPI for small print or professional printing, and 100 DPI for the smallest file.

What is PDF?

PDF (Portable Document Format) is a document format introduced by Adobe in 1993. Files use the .pdf extension.

PDF was created by Adobe to show documents the same way on any device and printer. A PDF file describes pages with text, fonts, vector graphics and images at fixed positions. It became an open ISO standard in 2008, and there are special variants such as PDF/A for archiving and PDF/X for printing.

PDF is the right choice for documents that must look the same everywhere, such as contracts, invoices, forms, manuals, reports and files for printing. It also supports digital signatures, fillable forms, comments and password protection.

PDF is hard to edit, because text is stored as positioned pieces, not as flowing paragraphs. Converting a PDF to Word may change the layout. Scanned PDFs contain pictures of text, not real text, unless OCR has been applied.

All major web browsers open PDF files directly. Windows, macOS, iOS and most Android phones include a PDF viewer, and Adobe Acrobat Reader and many free apps can view, annotate and fill PDF forms on all platforms.

Why use FansBond Flatten PDF

Most online converters upload your files to their servers. FansBond Flatten PDF does the work inside your browser instead, using WebAssembly and modern browser APIs. Your files stay on your device, which is safer for private photos, contracts and unreleased work, and it is often faster because nothing has to upload or download.

There are no queues, no watermarks and no account. Once the page has loaded, the tool keeps working even on a slow connection.

Tips for the best result

• Check the result before you send it. If fields can still be edited, for example because they contain characters the standard font cannot show, use Whole page to image instead.
• Whole page to image is the reliable way to remove text hidden under Whiteout or content outside a cropped area, because only what is visible on the page is kept.
• Keep an unflattened copy of the form. After flattening, the answers can no longer be changed in the fields, so corrections need the original file.
• Whole page to image often makes the file larger. If it is too big, choose a lower resolution or run the result through PDF Compressor.

How Flatten PDF works in your browser

The PDF is opened with pdf-lib, an open-source PDF library that runs in your browser. Pages are copied, rotated, resized or cropped at the PDF object level, so text stays text and vector graphics stay sharp.

Because the original page content is copied rather than re-rendered, there is no quality loss. The only exception is an option that explicitly turns pages into images. The new PDF is assembled in memory on your device and offered as a download.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. Flatten PDF works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.