Working with your PDF

Castleaf edits PDFs in your browser. Open a file, make a change, review the result, and export a new copy.

Open a document

Choose Open or drop a PDF into the workspace. The editor accepts files up to 30 MB. Sample document and Sample form let you try the tools without choosing your own file. Your source file is retained separately from committed edits.

Edit original text and objects

Select lets you pick original text, images and supported shapes. Related text runs are selected as Text sections by default. Alt-click or Individual run selects a single run. Drag to move a selection, use Properties for exact positions, or select Edit text for supported text.

Text-section editing keeps the original line slots. It does not reconstruct an arbitrary paragraph or add new original lines. Automatic fitting can shrink replacement text to its original run’s dimensions; use Preview text in PDF before applying a change. Unsupported fonts, complex scripts and protected structures can limit editing.

Add text and marks

Add text creates a new text mark. Choose Text box for explicit word wrapping, alignment and line spacing. Overflow blocks Apply and export rather than cutting text off. Highlight, Draw, Rectangle and Add image create marks above the document. Undo and Redo let you review committed changes.

Drawing over words is not secure redaction. A drawn signature is only a visual mark and is not a digital signature.

Arrange pages and fill forms

The Pages panel provides move, rotate, duplicate, delete, merge and extract actions. Some structured documents restrict these operations to protect their annotations, forms, links or tags. The Forms tab displays supported fillable fields; preview the filled page before exporting.

Save and recover your work

Export PDF downloads the edited PDF. Preview export lets you inspect the output first. Save editable session downloads a .folio file containing the original PDF, committed edits and project fonts so you can continue later.

Local autosave keeps the latest document and committed edits in this browser. Restore draft appears when saved work is available. Only one tab can autosave at a time. Browser clearing, private browsing, storage limits or eviction can prevent or remove recovery. A session download is the durable, portable backup.

Know the limits

This editor does not provide OCR, secure redaction, arbitrary original-paragraph reflow, image pixel editing or complex-script shaping. Review exported documents before relying on them, especially where layout, forms, links or accessibility structure matter.

This guide describes the current web build. Files, sessions and local drafts are unencrypted on your device. See Privacy and local storage before opening confidential documents.