Can these tools open password-protected PDFs?

Not yet. The PDF libraries used here can decrypt protected files in principle, but the current tools expect an unlocked input. Remove the password in your operating system viewer first, then open the file in the tool.

What is the largest PDF I can process?

Nothing is enforced. Practical limits depend on device memory. A modern laptop handles 200 MB PDFs without trouble. Mobile phones may stall on anything above 50 MB.

Are hyperlinks and form fields preserved?

Hyperlinks and basic form fields survive most operations because pdf-lib carries them across the page-tree edits. Document outlines, also known as bookmarks, can be dropped when merging files from different sources.

Why is the compressed PDF sometimes larger?

PDFs that already store text efficiently have little redundancy left. Compression adds a small encoding overhead that can exceed the savings. Try a lower image-quality setting or accept the file as final.

Can the tools extract text from a scanned PDF?

Only if the scan already contains a text layer from an OCR pass. The text extractor reads the embedded text stream. Pure image scans need to go through an OCR step first.

Do the tools work on mobile?

Yes. Safari and Chrome on iOS and Android both run pdf-lib and PDF.js. Drag and drop falls back to a tap-to-pick file flow on touch devices.

What happens to my PDF when I close the tab?

It is released from memory immediately. There is no IndexedDB cache, no service worker holding the file, and no blob URL kept after the tab closes.

Complete guide to PDF tools

What are PDF tools?

PDF tools are utilities that read or rewrite a Portable Document Format file. The category spans merging, splitting, compression, rotation, watermarking, page-number stamping, text extraction, and conversion to or from image formats.

When to use them

PDF tools handle the small surgeries that come up around documents.

Three separate PDFs need to become one before filing or sharing.
A 50-page report needs the appendix split off and circulated separately.
A scanned document came in upside-down and every page needs rotating 180 degrees.
A draft needs a diagonal “DRAFT” or version-number watermark before review.
An exam booklet or printable handout needs page numbers stamped before printing.
Several phone photos need stitching into a single document for upload elsewhere.

Browser-based versus server-based

Browser-based PDF tools process the file inside the current tab using pdf-lib for edits and PDF.js for rendering. Both libraries are pure JavaScript that runs in your browser, with no upload step.

The trade-off versus a server-side service is throughput. A browser tab is bound by device memory and a single thread. Merging two 20 MB PDFs runs in well under a second on a modern laptop. Pushing a 500 MB scanned book through pdf-lib in a phone browser is going to stall.

Server-side PDF pipelines win for batch jobs, OCR over thousands of pages, or printer-bound PDF/X validation against ICC color profiles. For everyday operations on a handful of files, the browser route is simpler, faster, and keeps the document on your own machine.

Tool comparison

Tool	Primary use	Output / options
Merge PDF	Combine files	Multiple PDFs in, single PDF out
Split PDF	Extract pages or ranges	Page list or range syntax
PDF to image	Rasterize pages	JPEG or PNG per page
Image to PDF	Wrap images as PDF	JPG, PNG, WebP, GIF input
Rotate PDF	Fix orientation	90, 180, 270 per page
Compress PDF	Reduce size	Lossless or image re-render
Add page numbers	Stamp numbers	Position, start, size controls
PDF watermark	Diagonal watermark	Opacity, size, color
Extract text	Get plain text	Copy or download .txt
Delete pages	Remove pages	Thumbnail picker
Reorder pages	Drag into new order	Drag-drop reorder

Common workflows

Compile a multi-page expense report. Photograph each receipt, run them through image to PDF, then use merge PDF to attach a cover sheet. Add page numbers so the accounts team can reference items by page.

Prepare a contract for circulation. Use delete pages to strip the internal markup pages, apply PDF watermarkwith “DRAFT”, then compress PDF so the file fits an email attachment limit.

Convert a research PDF into editable notes. Run extract text to pull the body copy, then export specific figures with PDF to image for use in slides or blog posts.

Format primer: PDF, PDF/A, PDF/X

The base PDF formatis a container for text, vector paths, raster images, and fonts. It is the default whenever a file is referred to as “a PDF”.

PDF/A is an archival profile. It bans external dependencies such as JavaScript and linked fonts so the document remains readable decades from now. Government and legal archives often require PDF/A compliance.

PDF/X is a print-production profile. It requires embedded color profiles, prohibits transparency that the print pipeline cannot reproduce, and pins font subsets. Most print shops expect PDF/X-1a or PDF/X-4 for offset jobs.

Frequently asked questions

What is a PDF tool?: Any utility that reads or modifies a PDF document. The category covers merging, splitting, compression, rotation, watermarking, page-number stamping, text extraction, and conversion to or from image formats.
Can these tools open password-protected PDFs?: Not yet. The PDF libraries used here can decrypt protected files in principle, but the current tools expect an unlocked input. Remove the password in your operating system viewer first, then open the file in the tool.
What is the largest PDF I can process?: Nothing is enforced. Practical limits depend on device memory. A modern laptop handles 200 MB PDFs without trouble. Mobile phones may stall on anything above 50 MB.
Are hyperlinks and form fields preserved?: Hyperlinks and basic form fields survive most operations because pdf-lib carries them across the page-tree edits. Document outlines, also known as bookmarks, can be dropped when merging files from different sources.
Why is the compressed PDF sometimes larger?: PDFs that already store text efficiently have little redundancy left. Compression adds a small encoding overhead that can exceed the savings. Try a lower image-quality setting or accept the file as final.
Can the tools extract text from a scanned PDF?: Only if the scan already contains a text layer from an OCR pass. The text extractor reads the embedded text stream. Pure image scans need to go through an OCR step first.
Do the tools work on mobile?: Yes. Safari and Chrome on iOS and Android both run pdf-lib and PDF.js. Drag and drop falls back to a tap-to-pick file flow on touch devices.
What happens to my PDF when I close the tab?: It is released from memory immediately. There is no IndexedDB cache, no service worker holding the file, and no blob URL kept after the tab closes.

Related concepts

pdf-lib handles every edit operation in the tools above.
PDF.js renders pages to a Canvas for thumbnails and previews.
OCR covers what to do with image-only scans.
Image tools guide pairs with image-to-PDF and PDF-to-image flows.
Text tools guide picks up where extract-text leaves off.

Reviewed and tested May 25, 2026.