PDF Editor

Can I edit existing text in the PDF, or only add overlays?

Only add overlays. Editing existing PDF text is fundamentally different from the overlay approach most online editors take — it requires parsing the exact text positioning, font metrics, and line-break logic that was used by the PDF producer, which is information that is not preserved inside the PDF itself. Adobe Acrobat Pro can do limited in-place text editing because it has access to internal font metrics and heuristics, but even Acrobat struggles with justified text, hyphenation, and non-Latin scripts. For content changes, edit the source document (Word, Pages, Google Docs) and re-export the PDF.

Are my annotations visible in other PDF viewers or only this tool?

Visible in any standard PDF viewer — Adobe Reader, macOS Preview, Foxit, PDF-XChange, Firefox's and Chrome's built-in viewers. Because the annotations are stored as standard PDF annotation objects per the PDF specification, they render identically regardless of viewer. The one exception is flattened annotations — those are written directly into the page content stream rather than as annotation objects, so they appear as part of the page content in every viewer and cannot be toggled off. For collaborative review workflows where the recipient needs to accept or reject your markups, do not flatten; for final distribution, flatten so recipients cannot modify.

Is my document uploaded to a server for editing?

No. The editor runs entirely in your browser tab. PDF.js renders the pages locally, pdf-lib writes the annotations and saves the output, and the result downloads as a Blob. No fetch request carries document contents to any server. This matters for the common editor use cases — filling in rental applications with SSN data, signing contracts with PII, redacting logs with customer identifiers — where uploading to a server-side editor creates a compliance exposure. Verify in devtools Network tab that no outbound requests contain your file data during editing or saving.

Will my e-signature from this tool be legally valid?

In most jurisdictions a scanned signature image or typed signature meets the baseline legal test for an electronic signature (the US ESIGN Act, EU eIDAS for simple e-signatures). What is valid is not the same as what is secure — a pasted image signature can be copied and reused by anyone who receives the document. For higher-assurance signatures (real estate closings, large contracts), use a signature platform like DocuSign or Adobe Sign that applies cryptographic signatures with an audit trail binding the signer's identity. For everyday signing of NDAs, SOWs, and expense reports, an image signature via this editor is typically accepted and legally sufficient.

Can I add pages from other PDFs while editing?

Not directly within this editor — its scope is annotation and form-fill on the existing page set. For combining PDFs, use the pdf-merger tool which is purpose-built for multi-document assembly. A common workflow: use pdf-merger to assemble the full document first, then open the merged output in the pdf-editor to add annotations, signatures, or form fills. Or annotate each source PDF separately, then merge the annotated versions. Keeping the tools separate makes each one simpler to use reliably than a single all-in-one editor that juggles more state than it needs to.