PDF guides, without the fluff
How to get things done with a PDF — and the things about the format that trip people up. Written by the people who built the tools, which mostly means we will tell you where they stop working.
Get it done
Step-by-step guides for the jobs people actually need doing, each one wired to the tool that does it.
2 min readHow to merge PDF files
Combine several PDFs into one document, choose the page order, and keep the text selectable — without uploading anything.
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2 min readHow to reduce PDF file size
What actually makes a PDF smaller, why some files barely shrink at all, and how to compress one without wrecking the text.
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2 min readHow to password protect a PDF
Encrypt a PDF so it cannot be opened without a password — and understand exactly what that password does and does not protect.
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2 min readHow to convert a PDF to JPG
Turn PDF pages into images, pick a resolution that suits the destination, and know when PNG is the better choice.
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5 min readHow to split a PDF into separate files
Cut one PDF into several, either every N pages or at points you choose — and why typing “3-7” does not do what you think.
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6 min readHow to delete pages from a PDF
Remove the pages you do not want and keep everything else — plus the one thing a page delete quietly takes with it.
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5 min readHow to extract pages from a PDF
Pull selected pages into a brand-new document, and understand why the page order you tap in is not the order you get.
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5 min readHow to rearrange pages in a PDF
Drag pages into a new order visually, drop the ones you do not need, and rebuild the document in one pass.
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5 min readHow to rotate pages in a PDF
Turn sideways scans upright and save them that way — and why rotation is the one edit that costs you nothing at all.
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5 min readHow to crop a PDF
Trim margins and scanner edges off your pages, apply one crop to everything or a different crop per page.
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6 min readHow to flatten a PDF
“Flatten” means two different things. Pick the wrong one and you either lose your text or fail to lock anything down.
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5 min readHow to convert JPG images to PDF
Turn photos into a PDF, one per page, and choose between pages that hug each image or a uniform A4 sheet.
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5 min readHow to convert PNG images to PDF
Put screenshots, diagrams and logos into a PDF — and what really happens to a transparent PNG on the way in.
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6 min readHow to convert a TXT file to PDF
Typeset a plain-text file into a paginated PDF, and know in advance which characters will not survive the trip.
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6 min readHow to convert HTML to PDF
Turn a saved web page or pasted markup into a PDF — and why no browser-based tool can take a URL.
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5 min readHow to convert a PDF to PNG
Export pages as lossless PNGs, keep transparency intact, and know exactly when PNG beats JPG.
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5 min readHow to extract images from a PDF
Get the real embedded photos out of a document rather than a screenshot of the page — and what gets missed.
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5 min readHow to prepare a PDF for archiving
What PDF/A actually demands, what a browser can honestly do about it, and when you need a different tool entirely.
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5 min readHow to add page numbers to a PDF
Stamp real, searchable page numbers anywhere on a document, start from any number, and handle a cover page.
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5 min readHow to add a watermark to a PDF
Stamp DRAFT or CONFIDENTIAL across every page, control how it looks, and see why a watermark is not security.
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5 min readHow to annotate a PDF
Highlight, draw and add notes to a document — and why your page text stays selectable afterwards.
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5 min readHow to fill in a PDF form
Complete a fillable form and save it, tell a real form from a picture of one, and lock the answers when you are done.
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5 min readHow to remove a password from a PDF
Take the password off a PDF you can already open, and understand why no honest tool can recover one you lost.
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5 min readHow to sign a PDF
Draw or type a signature and place it on the page — and where this sits relative to a legally-binding e-signature.
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4 min readHow to compress a PDF in Adobe Acrobat — and free, without it
Compress a PDF the way Acrobat does — but free and without uploading it. Pick a level; it re-encodes the embedded photos in your browser and tells you how many it changed.
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4 min readHow to merge PDF files in Adobe Acrobat — and free, without it
Combine PDFs the way Acrobat's Combine Files does — free and without uploading them. Drag the files into order and merge, all in your browser, with no subscription.
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5 min readHow to convert a photo to PDF on iPhone
Open JPG to PDF in Safari, add photos, drag them into order, and tap Create PDF — built on your phone, nothing uploaded. Plus the iPhone quirks: HEIC and sideways photos.
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5 min readHow to sign a PDF on iPhone — with Markup, and without it
To sign a PDF on an iPhone, open it in Files or Mail, tap Markup, then Add Signature and draw with your finger. When Markup is not offered — a Gmail preview, a link in Chrome — open Sign PDF in Safari instead.
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6 min readHow to edit a PDF on iPhone — and what “edit” really means
To edit a PDF on an iPhone, open it in Files and tap Markup, or use Annotate PDF in Safari, to draw, highlight and add text. Rewording the original text needs a converter.
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3 min readHow to compress a PDF without losing quality
No PDF compressor shrinks photographs without some quality loss — re-encoding a JPEG is lossy by nature. What stays lossless is the text and vector graphics, which are never touched. Pick Low for near-invisible loss.
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5 min readHow to convert a PDF to JPG on iPhone — beyond the screenshot
To convert a PDF to JPG on an iPhone, open PDF to JPG in Safari, choose a resolution, and tap Convert. Every page is rendered on the phone, nothing uploaded — one page saves as a JPG, several arrive as a .zip.
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5 min readHow to convert a PDF to Word on iPhone — and what iOS will not do
To convert a PDF to Word on an iPhone, open PDF to Word in Safari and pick your file — the .docx is rebuilt on the phone, nothing uploaded. iOS has no built-in converter, so every other route either uploads your file or wants an app.
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4 min readHow to delete pages from a PDF on iPhone — without an app
To delete pages from a PDF on an iPhone, open Delete Pages in Safari, tap the page numbers you want gone, and tap Remove — the PDF is rebuilt on the phone, nothing uploaded. iOS 26 Preview can do it too; older iPhones have no built-in way.
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5 min readHow to unlock a PDF on iPhone — with the password, not without it
To unlock a PDF on an iPhone, open Unlock PDF in Safari, pick the file, type the password it opens with, and tap Unlock — decrypted on the phone, nothing uploaded. iOS has no built-in remover, and no honest tool takes a password off a file you cannot already open.
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5 min readHow to rotate a PDF on iPhone — and make the turn stick
To rotate a PDF on an iPhone, open Rotate PDF in Safari, tap each sideways page ninety degrees at a time, then Apply — the turn is written into the file itself, so it is permanent and loses no quality. Apple Preview and Files can rotate too, when they show the option.
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3 min readHow to tell if a PDF tool is uploading your file
Prove whether any online tool sends your file to a server, in under a minute, using tools already built into your browser. No trust required.
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3 min readHow to convert a PDF to Word
Turn a text-based PDF into an editable .docx in your browser — text, headings, bold and italic come back; tables, images and exact layout do not.
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3 min readHow to convert Word to PDF
Turn a Word .docx into a PDF with real, selectable text, in your browser and with no upload. Headers, footnotes and exact page breaks do not carry over.
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3 min readHow to make a scanned PDF searchable
To make a scanned PDF searchable, run it through OCR: it reads the text in the page image and lays an invisible, selectable copy over the scan. The page looks identical — English only, and words it is unsure of are dropped, not buried.
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3 min readHow to convert a CSV to PDF
To convert a CSV to PDF, drop the file in and download — it is parsed into a real, selectable table, not a screenshot, with the delimiter detected for you. It is a plain table, though: numbers are not formatted and nothing is calculated.
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3 min readHow to convert a PDF to text
To pull the text out of a PDF, extract its text layer: it reads the real characters the file already stores and hands you plain .txt to copy or download. It works on text-based PDFs — a scan has no text layer, so OCR that first.
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4 min readHow to convert a PDF to Excel
To turn a PDF into a spreadsheet, extract its table: the tool reads the text in your browser and infers rows and columns from where the characters sit, writing one sheet per page. It works on genuinely tabular PDFs, and never on a scan.
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4 min readHow to redact a PDF
To redact a PDF, drag a black box over any text or image you want gone, then apply. Each page you mark is flattened to an image with the box baked in, so the words underneath are removed from the file, not merely hidden behind a rectangle.
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4 min readHow to convert a PDF to Markdown
To convert a PDF to Markdown, extract its text and let the tool infer structure: larger text becomes a # or ## heading, bold and italic runs become emphasis, and you get clean .md to copy or download. It works on text-based PDFs, never on a scan.
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4 min readHow to scan a document to PDF
To scan a document to PDF, use your device camera in the browser: each capture becomes a page and the pages are assembled into a PDF on your device, with no app and nothing uploaded. Every page is a photo, so run OCR after if you need searchable text.
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4 min readHow to compare two PDFs
To compare two PDFs, extract the text of both and diff it line by line: added lines show in green, removed lines in red, with a count of each. It compares what the words say, not how the pages look, so both files need a real text layer.
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4 min readHow to edit a PDF’s metadata
To edit a PDF’s metadata, open Edit Metadata and its title, author, subject, keywords, creator and producer are read into editable fields. Change any of them, or clear them all, and save a new copy — the pages stay untouched.
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4 min readHow to convert Excel to PDF
To convert Excel to PDF, drop in your .xlsx and each sheet becomes a table of real, selectable text — in your browser, nothing uploaded. Columns are spread to fit the page width, so a wide sheet wraps instead of having its right-hand columns cut off.
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4 min readHow to add bookmarks to a PDF
To add bookmarks to a PDF, drop your file into Edit Bookmarks. Any outline it already has is listed against the right page; rename entries, re-point them, add new ones or clear the lot, then download a copy — in your browser, nothing uploaded.
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5 min readHow to measure distances and areas on a PDF to scale
To measure a PDF to scale, open Measure PDF and draw a line over something whose real length you know, then type that length in to calibrate the page. After that, click two points for a distance, or trace a shape for its area and perimeter.
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5 min readHow to add and remove file attachments in a PDF
To attach a file to a PDF, open PDF Attachments, drop the PDF in, and click Add a file to embed anything from your device — a spreadsheet, an image, even another PDF. Download the new copy and the file rides inside it.
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How PDFs actually work
The parts that surprise people — why a crop is not a redaction, why your file is enormous, and what “runs in your browser” really means.
7 min readWhat a PDF page actually is
A page is not a sheet of paper. It is a media box, a crop box and a rotation — and when they disagree, tools break.
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8 min readVector and raster: the two kinds of mark in a PDF
Why some PDFs stay razor sharp at any zoom, why others turn to mush, and why turning one into the other is a one-way trip.
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6 min readWhat “lossless” actually means in a PDF tool
Copying a page and re-photographing it both get called lossless. Only one of them is — here is which of ours are which.
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7 min readWhy your filled-in PDF form comes back blank
The boxes are still there and nothing is in them. A form lives at the document level, and most edits rebuild the document.
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6 min readWhat a PDF password actually protects
There are two passwords, and the one that restricts printing and copying is a polite request your viewer is free to ignore.
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7 min readWhat your PDF quietly says about you
Every PDF carries a block of text you did not write: which program made it, when, and often who. Including ours.
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8 min readWhy you cannot select the text in a scanned PDF
A scan is a photograph of a document, not a document. Your eyes read it; your cursor finds nothing there.
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6 min readWhy your PDF text turns into question marks
The built-in fonts physically cannot hold Cyrillic, CJK or emoji — and some tools tell you, while others just mangle it.
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7 min readWhy a PDF looks different on someone else’s screen
A PDF either carries its fonts or names them and hopes. Guess which one moves your line breaks.
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6 min readWhy editing a PDF is so awkward
PDF stores where every glyph sits, not what the sentence is. There is no paragraph to reflow — because there is no paragraph.
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2 min readCropping a PDF does not remove anything
A crop hides content, it does not delete it. If you cropped something sensitive out before sharing, it is still in the file.
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3 min readWhat “runs in your browser” actually means
Most PDF sites upload your document to a server they own. Here is what the alternative is, and how to check the claim yourself.
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2 min readWhy your PDF is 40MB
Almost always photographs. A look at what is actually inside a bloated PDF, and why a text-heavy file will not compress.
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6 min readWhat OCR can and can’t get back from a scan
OCR does not make a scan editable. It reads the pixels and lays invisible, searchable text over the page — English only, low-confidence words dropped.
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6 min readA black box over text is not redaction
A rectangle drawn over text leaves the text in the file, still selectable. Real redaction re-renders the marked page to an image so the words are gone.
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5 min readWhere your PDF’s bookmarks go when a tool rebuilds it
Bookmarks live at the document level, not on the pages — so any tool that rebuilds a PDF from its pages (merge, split, reorder) quietly leaves them behind.
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5 min readThe files hidden inside your PDF
A PDF can carry whole files inside it, invisible on the page. What they are, how to find them, and why removing one has to delete the bytes, not the pointer.
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5 min readA PDF has no idea how big anything on it really is
A PDF records positions in points, not real-world scale. To measure a plan you calibrate against a known length — and areas scale by the square.
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5 min readDrawn, typed, digital: three kinds of PDF signature
Three different things get called a PDF signature: a drawn picture, a cryptographic seal, and an e-signature service. Which one you actually need, and why.
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6 min readWhat PDF/A actually requires
PDF/A demands embedded fonts and a colour profile a browser cannot reliably supply — so honest online tools do archival cleanup, not certified conversion.
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5 min readWhy splitting a PDF barely shrinks the pieces
Splitting a PDF does not shrink the pieces. Page count is not file weight — the weight is images, and splitting copies them across untouched.
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5 min readWhat “extract images” actually pulls out of a PDF
Extracting images pulls the real embedded pictures out at full resolution — not a page screenshot. What it finds, what it dedupes, and what it quietly misses.
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5 min readWhy “page 1” of a PDF isn’t always the first page
The page a tool calls “page 3” is the third sheet in the file, not the one printed 3. There are three different page numbers, and they routinely disagree.
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3 min readIs it safe to upload a PDF to an online tool?
Usually nothing goes wrong — but you are handing a copy of your file to a stranger's server. How to judge the real risk, and when not to take it at all.
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3 min readOnline, offline, or in-browser? The difference that matters
"Online" and "offline" are not the two choices — there are three. The middle one runs in your browser: delivered online, but your file stays local.
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3 min readDo online PDF tools really delete your files?
Most say they delete uploads within an hour. That is usually sincere, entirely unverifiable, and quietly leaves backups and logs out of the promise.
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3 min readHow to edit a PDF without uploading it anywhere
Fill, sign, annotate, stamp and redact a PDF entirely in your browser — no upload. What you cannot do that way is reflow the original text, and why.
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