PDF flattening merges form fields, annotations, and signature layers permanently into the page content, converting an interactive PDF into a static document that looks identical in every viewer. This tool offers two processing paths: local mode keeps the file in your browser; cloud mode uploads it for higher-quality output with optional password protection.
When you need to flatten a PDF
A PDF with fillable fields or annotations can be modified by whoever receives it, and may display differently across PDF readers. Flattening eliminates both problems:
- Submitting a completed contract or application so the content cannot be changed
- Locking an annotated draft as the definitive version
- Removing form fields from a template before distribution
- Ensuring consistent layout when printing on different printers or operating systems
Local mode vs. cloud mode: what actually differs
Local mode
- File never leaves the browser
- First attempts direct form-field flattening
- Falls back to rendering each page as an image if direct flattening fails
- Text in the image fallback path is NOT selectable or searchable
- Complex fonts may render as garbled characters or boxes
Cloud mode
- File uploaded to server; higher quality and consistency
- Text remains selectable (depends on source PDF structure)
- Supports adding a password to the flattened output
- Supports output compatibility levels from PDF 1.4 to 2.0
- Better choice for complex layouts or documents going to external recipients
Local quality: Standard vs. HD
The quality setting only matters when local mode triggers the image fallback path — that is, when the PDF cannot be directly flattened in the browser. Standard renders at normal resolution: faster, smaller output. HD renders at higher resolution, keeping fine text and diagrams crisp, but takes longer and produces a larger file. If the source PDF has no complex fonts, direct flattening succeeds and the quality setting has no effect.
Cloud compatibility levels
The output compatibility level (PDF 1.4 through 2.0) determines which PDF readers can open the result. Acrobat 6 and older require 1.4 for full compatibility. Modern use cases are fine with 1.7 or the default.
Adding a password after flattening
Cloud mode lets you set a password on the flattened output. The recipient needs the password to open the file. This protects only the open permission — the password does not prevent the recipient from copying or printing once they have access.