Alternate & Mix PDF Pages
Interleave two PDFs a page at a time. Free, and runs entirely in your browser — nothing you enter is uploaded, stored or sent to a server.
About Alternate & Mix Pages
Takes one page from each document in turn, instead of putting one document after another. There is exactly one situation that needs this and it is extremely common: a two-sided stack scanned on a feeder that only reads one side, giving you the fronts in one file and the backs in another.
Merging those two files end to end produces a document that looks fine and is wrong. Page 1, page 3, page 5… then page 2, page 4, page 6. Nothing is missing, nothing is corrupt, and it is unreadable in the way that takes twenty minutes to diagnose. Interleaving is the fix, and it takes one click.
The second file is usually backwards as well, because the stack was turned over as a block: the last sheet's reverse was scanned first. The reverse switch handles that, and the preview is the way to check which of the two cases you have before saving.
Where it helps
- Fixes the two-pass duplex scan, which is the reason most people go looking for this.
- Reverses the second document on request, for a stack that was turned over as a block.
- Works with more than two files, rotating through all of them.
- Documents of different lengths do not break it — the shorter ones simply drop out.
- Pages are copied wholesale, so nothing is re-rendered.
- The files never leave your browser.
Limits
- Bookmarks and internal links are not carried over from either document.
- It cannot tell which file is which: choosing them in the wrong order gives a document that is still interleaved and still wrong.
- Page sizes are whatever each document brought; a mixed pair comes out mixed.
- Form fields with the same name in both documents will collide.
- Password-protected files must be unlocked first.
Frequently asked questions
Why not just merge them?
Because merging concatenates. Two files of ten pages merge into pages 1,3,5…19 followed by 2,4,6…20. Interleaving gives 1,2,3,…,20, which is the document you actually scanned.
How do I know whether to reverse the second file?
Look at its first page. If it is the back of the *last* sheet rather than the back of the first, the stack was turned over as a block and the file needs reversing. The preview after running shows whether you got it right.
What happens if the two files are different lengths?
They alternate until the shorter one runs out, and the remaining pages of the longer one follow at the end. That is usually a sign that a sheet was missed on one of the passes — worth checking before filing it.
Can I interleave every two pages instead of every one?
Not directly. Split the documents into the groups you want first, then merge in the order you need with the organiser.
Related tools
- Merge PDF — Join several PDFs into one document
- Reverse Pages — Flip a PDF's page order end to end
- Rearrange PDF Pages — Put a PDF's pages in a different order
- Split PDF — Cut a PDF into separate documents
- Icon Font Generator — Build a web font from SVG icons or an SVG font
- Image Converter — Convert between PNG, JPEG, JFIF, WebP, GIF, HEIC and SVG
More Images & Files tools
- Icon Font Generator — Build a web font from SVG icons or an SVG font
- Image Converter — Convert between PNG, JPEG, JFIF, WebP, GIF, HEIC and SVG
- Image Resizer — Resize to a size, a proportion or a longest side
- Crop Image — Cut a rectangle out, or trim a flat border away
- Rotate Image — Turn by a right angle or any angle, and flip
- Image Base64 Converter — Turn an image into a data URI for CSS or HTML, and read one back
- WebP Converter — To WebP for the web, or back out of it
- SVG Converter — Draw an SVG at any size, or wrap a bitmap in one
- Background Remover — Take a flat background out and keep the subject
- Image Compressor — Resize and re-encode images to save bytes
- Image Optimizer — Strip metadata and redundant markup without touching the picture
- Favicon Generator — Build favicon PNGs and a multi-size .ico
- File Checksum — Verify a download, and work out which algorithm made the checksum
- QR & Barcode Reader — Read a code out of an image, and say what it does before you follow it
- MIME Detector — Identify a file from its magic bytes
- Office Password — Protect a Word, Excel or PowerPoint file with a password
- Office Password Remover — Remove the password from a Word, Excel or PowerPoint file
- Image Editor — Crop, straighten, adjust and cut out, with every step visible and reversible
- Passport Photo Maker — Passport and visa photos at each country's size, with head guides and a print sheet
- PDF Editor — Move and retype what is already on the page, reorder, annotate, stamp and sign, with the document in front of you
- PDF Viewer — Read, search and inspect a PDF without leaving the browser
- PDF Password & Permissions — Lock a PDF with AES-256, and say what a reader may print, copy or change
- PDF Password Remover — Strip the password from a PDF you can already open
- Merge PDF — Join several PDFs into one document
- Split PDF — Cut a PDF into separate documents
- Delete PDF Pages — Remove pages from a PDF and keep the rest
- Rearrange PDF Pages — Put a PDF's pages in a different order
- Rotate PDF — Turn a PDF's pages the right way up
- Compress PDF — Make a PDF smaller, by rebuilding it or redrawing it
- Watermark PDF — Stamp text or a logo across a PDF's pages
- Sign PDF — Put a signature and a date onto a PDF
- Edit PDF — Add text to a PDF page, and hide what is underneath
- PDF to Images — Turn every page into a PNG, JPG, WebP, GIF or JFIF
- OCR PDF — Read the text off a scanned PDF
- PDF to Word — Turn a PDF into an editable .docx that keeps its layout
- PDF to Excel — Pull a PDF's tables into a .xlsx workbook that keeps their formatting
- PDF to PowerPoint — Turn a PDF's pages into editable .pptx slides that look the same
- Word to PDF — Turn a .docx document into a PDF that looks the way it does in Word
- Excel to PDF — Print a .xlsx workbook to PDF with its formatting and page setup
- PowerPoint to PDF — Turn a .pptx deck into a PDF that looks the way the slides do
- Images to PDF — Turn photos or scans into one PDF document
- PDF to Text — Pull the text out of a PDF as plain text
- Crop PDF — Trim the margins off every page
- Page Numbers — Number the pages of a PDF
- Header & Footer — Put a running head or foot on every page
- Bates Numbering — Stamp sequential legal numbers across pages
- Reverse Pages — Flip a PDF's page order end to end
- Add Blank Pages — Insert empty pages anywhere in a PDF
- N-Up PDF — Put several pages on one sheet
- PDF Booklet — Reorder pages for folded booklet printing
- PDF Metadata — Read, change or strip a PDF's properties
- Flatten PDF — Make form answers part of the page
- PDF Overlay — Draw one PDF over or under another
- Combine to Single Page — Stack every page into one continuous strip
- Divide Pages — Cut every page in half or into quarters
- Posterize PDF — Tile a large page across several printable sheets
- Fix Page Size — Put every page onto one uniform sheet
- Page Dimensions — Measure every page, its rotation and its sheet
- Rotate by Any Angle — Turn pages by a fraction of a degree or more
- Remove Annotations — Strip comments, highlights, links and stamps
- PDF Attachments — List, extract, add or remove embedded files
- PDFs to ZIP — Package several PDFs into one archive
- PDF Bookmarks — Read, write or remove a PDF's outline
- Table of Contents — Build a contents page from the bookmarks
- Page Labels — Number front matter in roman and the body in arabic
- Sanitize PDF — Strip scripts, actions, attachments and metadata
- Extract Images — Pull every embedded picture out of a PDF
- Extract Tables — Turn a PDF's tables into CSV, JSON or Markdown
- PDF to Markdown — Convert a PDF into Markdown with its headings, emphasis, lists, tables and pictures
- PDF to JSON — Export a PDF's text as structured JSON
- Compare PDFs — See which pages of two PDFs differ, and by how much
- Remove Blank Pages — Find the empty pages, and take them out
- Invert PDF Colours — A dark-mode version of a document
- PDF to Greyscale — Convert every page to shades of grey
- Adjust PDF Colours — Brightness, contrast and saturation across a document
- Scanner Effect — Make a clean PDF look like a photocopy
- PDF Background Colour — Tint the paper behind the content
- Rasterize PDF — Flatten every page into a picture of itself
- PDF to CBZ — Turn a PDF into a comic book archive
- CBZ to PDF — Turn a comic book archive into a PDF
- Text to PDF — Set a plain text file as a document
- Markdown to PDF — Set Markdown as it renders: headings, emphasis, lists, code, quotes and tables
- JSON to PDF — Print a JSON file as an indented tree
- CSV to PDF — Set a spreadsheet export as a printed table
- XML to PDF — Print an XML document as an indented tree