Flatten PDF online, free

Flattening locks a PDF's interactive content in place: filled form fields, checkboxes, dropdowns, comments, highlights and stamps become ordinary, permanent page content that looks identical everywhere and cannot be edited, cleared or accidentally reset. What makes this flattener different is what it does not do to your document along the way.

Nothing is turned into a picture

Converting pages to images is the most common shortcut among free tools, and the reason their output comes back blurry on paper, several times the size, and impossible to search or copy text from. Here everything stays vector: the text remains selectable, the fonts remain fonts, and the file prints as sharply as the original. A six-page government form like the IRS W-9, with 23 live fields, flattens in about a tenth of a second — precisely because nothing is being rendered to pixels.

Answers re-rendered from their values, not from a broken picture

Form-filling software stores a pre-drawn image of each answer alongside the answer itself, and for Arabic, Hebrew, Persian and other non-Latin scripts that pre-drawn version is very often broken: disconnected letters, reversed direction, or empty boxes. Conventional flatteners bake that broken picture. This tool ignores it and re-renders every text answer from the actual stored value, with proper letter-joining and right-to-left layout. The same mechanism is why answers containing characters like a less-than sign, an ampersand or a line break come through intact instead of mangled.

Checkboxes that keep their real state, links that keep working

The classic flattening bug marks every radio button as selected. That does not happen here — checkboxes and radio buttons keep their genuine checked-or-not appearance. Hyperlinks are deliberately left clickable in every mode, so a flattened brochure keeps its working table of contents, where most flatteners silently destroy it.

Choose what gets flattened

Everything, only the form fields so comments stay editable, or only the annotations so the form stays fillable. That last mode is the one reviewers ask for: it makes the markup on a checked document permanent while leaving the signature and form layer alive.

Signatures, JavaScript and the honest edge cases

A signature field is flattened with its visual stamp preserved, but a signature's cryptographic validity cannot survive any modification of the file — that is true of every flattener ever written, and this one is the rare tool that says so, reporting exactly how many signature fields it baked. An optional cleanup switch strips the document's JavaScript: form validation scripts are dead weight once there is no form left, and embedded JavaScript is the classic carrier for malicious PDFs. On the real IRS W-9 we tested, which does ship with live JavaScript, the flattened output verifiably contains none. An XFA form — the dynamic kind some government agencies issue — gets a clear warning about what can and cannot be baked instead of a silent half-result.

Verified, not assumed

Unlike tools that simply hope the job worked, this one reopens its own output, counts every remaining interactive element, and reports a full flatten only when that count is zero — per file and for the whole batch. A document with nothing to flatten is returned normalised with a plain note saying so, rather than a fake success. Upload up to 10 PDFs per request, 300 MB in total, each with its own optional password; a damaged or wrongly-passworded file is named and skipped while the rest complete. Original names are preserved, Arabic and Chinese filenames included, and everything is deleted from the server an hour later.

What you get

• A real vector PDF — selectable text, sharp printing, no images
• Non-Latin form answers re-rendered correctly instead of baked broken
• Checkboxes that keep their true state and hyperlinks that keep working
• Three modes: everything, forms only, or annotations only
• Optional JavaScript removal, and honest reporting on signatures and XFA
• Verified output — a full flatten is reported only when zero elements remain

What's next?

Archiving the flattened file? Convert to PDF/A makes it a standards-compliant archive document. If the result is larger than you need, Compress PDF reduces it. And to pull the pictures out of a finished document, Extract Images from PDF gets the originals rather than a render of each page.