Home/Guides/PDF
📑PDF

Merge, Split, Compress: The Seven PDF Jobs Everyone Runs Into

Combine files, pull pages out, shrink a scan, fix a sideways page, reorder, convert — the right tool, the right order of steps, and the mistakes that cost a second attempt.

8 min read

The same seven PDF jobs, over and over

PDFs are the format documents arrive in when nobody expects you to edit them — which is exactly when you need to. Across offices, universities, clinics and kitchens the same handful of tasks come up: combine files, pull pages out, drop a blank page, make a scan smaller, turn a sideways page upright, put pages in order, and get a page into a place that only takes images. This guide walks through each job with the right tool, the right order of steps, and the mistakes that cost people a second attempt. All the tools mentioned run in your browser without uploading the file.

1. Combine several files into one

Tool: Merge PDF. Select all the files at once; they are combined in the order the file picker lists them, which is usually alphabetical. If the order matters — a cover letter before a CV before certificates — rename the files with a numeric prefix (01-cover.pdf,02-cv.pdf) before selecting. Pages are copied as objects, so nothing is re-rendered and text stays selectable. Bookmarks and document metadata do not carry across; set a title afterwards with Edit PDF Metadata if the file will be published.

  • Mixed page sizes are fine; each page keeps its own.
  • An encrypted file cannot be merged until it is unlocked (you need its password).
  • If some inputs are images, convert them to PDF first with Image to PDF, then merge.

2. Keep only some pages — or remove some

Three tools do variations of this, and picking the right one saves typing:

You wantToolYou type
A few pages out of a long fileExtract PDF PagesThe pages to keep: 2, 5-8
Most of a file minus a few pagesDelete PDF PagesThe pages to remove: 1, 14
Every page as its own file, or two halvesSplit PDFNothing — choose a mode

Page numbers are physical positions counted from 1, not the numbers printed on the pages. A report with a two-page cover has its printed “page 1” at position 3. Check the page count the tool shows after loading, or open the file in the PDF Viewer to confirm positions before typing ranges.

3. Make a file small enough to send

First find out why it is big. Open the file: if you can select text, it is a “real” PDF and its size comes from images or fonts; if you cannot, it is a scan and every page is a picture.

  • Scans and photo-heavy files: Compress PDF re-renders each page as a JPEG at the quality you choose and typically cuts size by 3–10×. Text becomes pixels — acceptable for a scan, which had no text layer anyway.
  • Text documents with a few large images: do not rasterize — the file may get bigger. Use the “Reduce file size” export in Acrobat, Preview or LibreOffice, which recompresses only the images, or shrink the images before re-exporting from the source document.
  • Files edited many times: Compact PDF rewrites the file cleanly, dropping the old versions that editors append on every save. It changes nothing on the page.
  • Only part of the file is needed: extracting the relevant pages is often the biggest saving of all.

4. Fix a sideways or upside-down scan

Tool: Rotate PDF. Rotation is stored as a page attribute, so it is instant and lossless. The tool rotates every page; for a single landscape chart in a portrait report, extract that page, rotate it, and merge it back in position. A page that is slightly crooked rather than sideways is skewed, not rotated — fix that in the scanner software or on the source image, since PDF only supports 90° steps.

5. Put pages in the right order

Tool: Reorder PDF Pages. Thumbnails of every page appear; drag them into sequence and save. Do this before adding page numbers, and after deleting blanks, so the numbers reflect the final order. A typical clean-up of a messy scan runs: Delete Pages (blanks) → Reorder → Rotate if needed → Add Page Numbers → Compress.

6. Get a page into an image, or an image into a PDF

DirectionToolNotes
PDF page → picture for a slide, post or formPDF to PNG (sharp text) or PDF to JPG (smaller)Extract the page first to avoid converting the whole file
Photos or scans → one PDFImage to PDFOne image per page at its own size; JPG, PNG and WebP accepted
Plain text → PDFTXT to PDFA4, Helvetica; hard-wrap long lines first
PDF → editable textPDF to TXTWorks only on files with a text layer; scans need OCR first

7. Mark, protect and label

  • PDF Watermark stamps DRAFT, CONFIDENTIAL or a recipient's name across every page — a deterrent and an identifier, not a lock.
  • Add Page Numbers writes real text in a corner of each page, so it prints sharply and is searchable. Start numbering from a page other than 1 when the file is a chapter.
  • Unlock PDF removes a password you know, so the file can be merged, compressed or printed without the prompt. It cannot recover a password you have lost.
  • Edit PDF Metadata sets the title that browsers show in the tab and Google shows in results, and clears an author field that may carry a personal name.
  • Crop PDF, Resize PDF Pages and N-Up handle margins, paper size (A4 ↔ Letter) and printing several pages per sheet.

Order of operations for common jobs

JobSteps
Application pack from separate filesImage to PDF (for any photos) → Merge → Add Page Numbers → Edit Metadata (title) → Compress if over the size limit
Clean up a phone-scanned documentDelete blank pages → Reorder → Rotate → Compress
Share one section of a contractExtract Pages → Watermark (recipient name) → send
Turn a report page into a slideExtract Pages → PDF to PNG → insert the image
Print a slide deck as a handoutN-Up (4 or 6 per sheet) → print
Archive a bank statement that needs a passwordUnlock (with the password) → Edit Metadata → store

What can go wrong

  • Compressing a text PDF made it bigger. Rasterizing replaces small text commands with big images. Use image-only recompression for text documents.
  • Page numbers or links are off after merging. Printed numbers are page content and do not change; internal links to pages that were removed point nowhere. Renumber with the tool and accept that cross-file links need a real editor.
  • “Failed to load” on an old file. Some PDFs have damaged structure. Run Compact PDF first — a clean rewrite repairs most cross-reference problems — or open and re-save in a desktop viewer.
  • A signed document lost its signature. Any rewrite invalidates a digital signature by design. Keep the signed original and circulate the modified copy separately.
  • Fonts look different after conversion. The PDF did not embed its fonts, so every viewer substitutes. Re-export from the source with fonts embedded.

Frequently asked questions

Are my files uploaded?

No. Every PDF tool here runs on pdf-lib and PDF.js inside your browser. The file is read into memory, processed, and offered back as a download; it never leaves your device, and the tools work with the network off once loaded.

Why do the tools not edit text inside a PDF?

PDF stores positioned glyphs, not flowing text, so editing a sentence means re-laying out the page — a job for a full editor such as Acrobat or LibreOffice Draw. These tools work at the page level, where operations are exact and lossless.

How big a file can the browser handle?

Desktop browsers process files of 100 MB or more comfortably; phones have less memory. Extract the pages you need before running heavy operations on very large files.

Can I password-protect a PDF here?

Not currently — browser-based encryption is not offered. Use Acrobat, macOS Preview (Export with password), LibreOffice or qpdf.

What is the difference between Split and Extract?

Split produces one file per page or two halves with no page list. Extract produces one file containing exactly the pages you list.

Will merging or splitting reduce quality?

No. Pages are copied byte-for-byte. Only Compress PDF, PDF to JPG and PDF to PNG rasterize, and their pages say so.

Tools mentioned in this guide