File conversion guides & tips
What each format is actually good for, where conversions go wrong, and how to fix them - written by the people who build the tools.
Every guide here is written against the tools on this site, so the limits and failure modes it describes are the real ones: the actual file size caps, the actual compression settings, the actual reasons a conversion comes back wrong. Where a guide says a conversion loses something, it says what and why.
Page-level work - combining, splitting, reordering, locking - and moving between PDF and image formats without destroying the text layer.
Why Your PDF to Word Conversion Comes Out Wrong
Blank pages, uneditable text, tables in the wrong places. Almost every bad PDF conversion traces back to one thing, and you can check for it in five seconds.
Merge, Split, and Reorder PDF Pages
Combining a packet, pulling one page out, fixing a sideways scan - the everyday PDF page jobs, and which tool does each one.
Password-Protect a PDF (and Remove It Later)
How to lock a PDF with a password, what 'unlocking' can and can't do, and when a watermark is the better tool for the job.
How to Convert PDF to Images (and Back Again)
A scanned form, a signature page, a single slide from a deck - here's the fast way to move between PDF and image formats.
Office
Word, Excel, PowerPoint and OpenDocument files going to PDF - what survives the conversion and the one thing that quietly shifts.
Images
Which image format to use when, what each conversion actually costs you in quality, and why iPhone photos refuse to open on anything that isn't an iPhone.
WebP: When It's Worth It, and When It Isn't
WebP makes smaller files than JPG or PNG at the same quality. It's also the format that half your desktop software still refuses to open.
HEIC to JPG: Why Your iPhone Photos Won't Open
Your iPhone saves photos as HEIC to save space, but half the internet can't read them. Here's what HEIC is and how to convert it.
Compress
Getting a file under an upload limit, and what is realistically squeezable versus what is already as small as it gets.
Downloading
How the media downloader works, what it deliberately will not do, and why a link sometimes fails.
Product
How the site is built and the decisions behind it - file retention, what we store, and what we don't.
Looking for the tool, not the guide?
Every tool page carries its own specifications, limits and troubleshooting section, so you can check the caps before uploading rather than after.