Flatten PDF Form

Turn supported filled AcroForm fields into fixed PDF page content, with an appearance audit.

Choose a filled PDF form to flatten locally

Existing AcroForm appearances only · 25 MiB · 200 pages · 100 fields. Other annotations are retained. This is not redaction, sanitization or tamper protection.

This tool processes its input contents in your browser instead of sending them to a processing service. Page, asset and fixed usage-measurement requests are described on the Privacy page.

Flatten supported PDF AcroForm fields locally using their existing appearances, with an explicit field audit.

How to use it

1Choose a filled PDF form or load the example.
2Review compatibility errors or the successful field audit.
3Download and inspect the flattened PDF while keeping the original.

Example

Input: Example form: Name Alex Rivera; Details checked selected
Output: 2 fields and 2 widget appearances flattened on 1 page; no editable form fields remain

Existing appearances only; other annotations are retained.

What happens to your data

PDF bytes, filenames and field names remain in this browser. Downloaded audits contain field names; fixed usage telemetry excludes document data.

Last updated November 2026

Make the filled fields in a supported PDF form part of its page content. Choose one PDF and download the flattened copy plus a field audit. The tool reuses each widget's existing normal appearance rather than guessing how its text, checkboxes or radio buttons should look. Your original stays unchanged.

How it works

One nonempty PDF up to 25 MiB, 200 pages, 100 fields and 300 widgets is processed locally with pdf-lib. Field widgets must belong to one page, have an existing normal appearance and use supported unscaled, unrotated appearance geometry. Text, checkbox, radio, dropdown, list and button fields are supported only when their appearances pass those checks. XFA, encryption, signatures and signature fields, reader-regenerated appearances, hidden or visibility-dependent widgets, unsupported field types and missing appearances are rejected as a whole.

The stored appearance stream is embedded in the page and the original field/widget references are removed. Page boxes, rotation and UserUnit entries are audited before saving. Appearance streams are not regenerated, so a previously stale appearance cannot be repaired automatically. Review every page of the downloaded file and keep the original. The audit lists the field names, types and widget counts; it contains no field values.

This is specifically form flattening. Other annotations, links, scripts, attachments and hidden document data are not comprehensively removed or flattened. It is not a general annotation flattener, sanitizer, redaction tool, encryption tool or protection against someone editing page content. No claim of tamper-proof or legally immutable output is made. Limits reduce browser workload but do not guarantee every permitted PDF is compatible. Clear or changing the source invalidates any old result; an operation already inside the PDF library may finish in memory, but its stale result is discarded.

Common use cases

Sharing a completed ordinary form without editable AcroForm fields
Keeping the stored field appearance in a form intended for printing
Auditing which fields were flattened before reviewing the saved document

Frequently asked questions

Will this make my PDF impossible to edit?＋

No. It removes supported editable form fields by placing their stored appearances into page content. A PDF editor can still alter that content. Flattening is not encryption, redaction or tamper protection.

Does it flatten highlights, stamps and every annotation?＋

No. This tool handles supported AcroForm field widgets. Other annotations are retained and counted; it is not a replacement for a general annotation-flattening workflow.

Why is my form rejected even though a viewer opens it?＋

A viewer may rebuild missing appearances or support XFA, signatures, hidden widgets or appearance transforms this tool cannot safely preserve. Save a standard filled form with valid appearances in a PDF editor, then try that copy.

Are form values uploaded?＋

No. PDF bytes and field names stay in browser memory. Fixed usage measurements may record actions and safe error codes, never the document, filename or field values. The optional downloaded audit contains field names, so review it before sharing.