Complete guide to PDF tools

By the inyourbrowser.com editorial team · Reviewed and tested September 30, 2026

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, cropping, metadata editing, text extraction, and conversion to or from image formats.

How to choose a PDF tool

Start from what is wrong with the file, or what its reader needs.

• If several files have to arrive as one document, combine them into one PDF, ordered with the up and down arrows. If some pages are still photos, turn the images into PDF pages first; each JPG, PNG, WebP, or GIF becomes one page.
• If only a few pages matter, extract them by page range, such as 1-3, 5. If naming the pages to drop is easier, delete the unwanted pages by clicking their thumbnails instead.
• If the pages are out of sequence, drag them into the right order. If the order is right but a scan came in sideways or upside down, turn the affected pages 90 degrees at a time, or every page by 90, 180, or 270 degrees at once.
• If the file is too big to email, shrink the file with the Lossless setting first, which keeps text selectable. High, Medium, and Low re-render every page as a JPEG image, which suits scans but makes text unselectable.
• If a scan shows dark scanner edges or wide margins, trim the pages to a rectangle you drag. The default mode rebuilds each cropped page as an image, so the trimmed area leaves the file; “Keep text selectable” only hides it, and anyone can restore it.
• If the document needs marking before it goes out, stamp page numbers at the bottom center, bottom right, or top right, starting from the number you choose, or lay a diagonal watermark such as “DRAFT” across every page and set its opacity, size, and color.
• If you need the words rather than the layout, copy the text out or download it as a .txt file. A scan without a text layer comes back empty and needs OCR first. If the look of a page matters, save the page as a JPEG or PNG at 1x, 1.5x, or 2x resolution.
• If the file carries an author name, the software that made it, or dates you did not mean to share, edit or strip its document properties.

For a side-by-side comparison with upload services and desktop software, see the PDF tools overview.

Tool comparison

How to modify a PDF in the browser

1. Pick a tool that matches the change you need. Merging joins files. Splitting extracts pages. Compression shrinks size. Rotation fixes orientation. Watermark stamps text. Choose by the verb that fits.
2. Drop the PDF into the tool. Drag the file onto the upload area or tap to select. The browser reads it into memory inside the current tab, where pdf-lib or PDF.js opens it.
3. Configure the operation. Reorder pages, pick a page range, enter watermark text, or choose a compression quality. Tools with page thumbnails, such as rotate and split, mark your choices on them before you download.
4. Download the modified PDF. Save the result to your device. The original file stays untouched; the download is a new file built in your browser.

Common workflows

Compile a multi-page expense report. Photograph each receipt, run them through photo to PDF, then join the result to a cover sheet. Number the pages so the accounts team can reference items by page.

Prepare a draft report for circulation. If it began as a scan, first crop away the scanner edges so only the page content shows. Take out the internal review pages (their content does not come along, but comments on the pages you keep do, so resolve those first), stamp “DRAFT” across each page, then compress it for email so the file fits an attachment limit. Before the file leaves the team, check its document properties for an author name or software version you did not mean to share.

Convert a research PDF into editable notes. Pull the body copy out as plain text, then export the pages that hold the figures as images for use in slides or blog posts.

Step-by-step versions: get a PDF under an email attachment limit, remove, reorder, and watermark pages before sharing, and extract and tidy the text of a PDF.

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

The base PDF format is 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, cropping, metadata editing, text extraction, and conversion to or from image formats.

Can these tools open password-protected PDFs?

The tools expect an unlocked input. The PDF libraries used here can decrypt protected files in principle, but the current tools do not ask for a password, so remove it in your operating system's PDF viewer first, then open the file in the tool.

What is the largest PDF I can process?

Up to 100 MB per PDF (Merge PDF allows 100 MB across all files). Larger files are refused before processing starts. Phones can still stall on files well below that, depending on memory.

Are hyperlinks and form fields preserved?

Tools that edit pages in place (rotate, watermark, page numbers, metadata, and lossless compress) keep hyperlinks, form fields, and bookmarks as they are. Tools that build a new file from pages (merge, split, delete, and reorder) keep links between the pages that stay and remove links to pages left out; form fields keep their values, but the new file has no document-level form, so viewers may no longer let you fill them in, and bookmarks are not carried over. Modes that turn pages into images (the High, Medium, and Low settings of compress, and cropped pages in crop's default mode) drop the links and fields on those pages.

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. When the result is not smaller than the original, the tool says so and offers no download.

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 page object: the structure that rotating, reordering, and deleting pages work on.
• Lossy compression: what the High, Medium, and Low settings of the compressor apply.
• Raster vs vector: why converting a PDF to images turns selectable text into pixels.
• PDF watermark: the difference between an overlay and a watermark stamped into the page.
• OCR: what an image-only scan needs before its text can be extracted.
• 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 September 30, 2026.