GUIDES
Practical help for digital tasks
Clear explanations that help you choose formats, protect privacy and get better results from the tools.Image guides
View tools →How to Reduce Image File Size Without Ruining Quality
Why the dimensions matter more than the quality slider, which format suits which picture, and how to tell when you have stopped gaining anything.
Read guide →JPG vs PNG vs WebP: Which Image Format Should You Use?
The real difference is what each format was built to compress. Once you know that, the choice makes itself for photos, screenshots, logos and the web.
Read guide →How to Convert HEIC to JPG Without Uploading Your Photos
Why an iPhone photo will not open on someone else's computer, how to convert it on your own device, and what the conversion costs you.
Read guide →Why Did My Compressed Image Come Back Bigger?
Compression tools sometimes return a file larger than the one you gave them. Here is why it happens, why PNG is the usual culprit, and what to do instead.
Read guide →Does Compressing an Image Lose Quality?
What lossy and lossless compression actually do to a picture, how much quality you can give up before anyone notices, and which choices are irreversible.
Read guide →How to Get an Image Under 2 MB (or 1 MB, or 500 KB)
A reliable order of operations for hitting a hard upload limit on a form, application or portal without turning your photo to mush.
Read guide →How to Remove Location Data From a Photo
What EXIF metadata records about you, when it actually leaks, and a straightforward way to strip it from an image without installing anything.
Read guide →What Happens to Transparency When You Convert PNG to JPG
Why a transparent logo turns into a white or black rectangle, how to tell in advance, and which formats keep an alpha channel.
Read guide →How to Compress Photos Without Uploading Them
Shrinking images on your own device, why compressing does not reliably strip the location data inside them, and what to do when the output comes back bigger.
Read guide →Pdf guides
View tools →How to Combine Multiple PDF Files Into One Document
Getting the order right the first time, what merging does to forms and bookmarks, and why the combined file is rarely the size you expected.
Read guide →How to Split a PDF and Extract Only the Pages You Need
How to extract a page range while keeping the original intact, and why the number printed on the page is so rarely the number the tool wants.
Read guide →Is It Safe to Upload a PDF to an Online Tool?
What happens to a document after you drop it on a website, which questions are worth asking, and how to tell a local tool from an uploading one.
Read guide →How to Make a PDF Small Enough to Email
Where PDF bulk actually comes from, what you can do about it without specialist software, and an honest account of what a browser can and cannot fix.
Read guide →How to Turn Photos Into a Single PDF
Combining images into one document for a form, a claim or an application — including how page sizes are decided and why the order of your files matters.
Read guide →How to Turn a PDF Into Images
When converting PDF pages to JPG or PNG is the right move, how to pick the resolution, and what you quietly give up the moment text becomes pixels.
Read guide →How to Rotate, Reorder and Delete PDF Pages
Fixing sideways scans, putting pages back in order and dropping the ones you do not need — and why a rotation sometimes refuses to stick.
Read guide →How to Merge PDFs Without Uploading Them Anywhere
Combining documents that must not leave your computer: what browser-based merging really does, how to prove no file was sent, and what it costs you.
Read guide →How to Split a PDF Safely When the File Cannot Leave Your Computer
Extracting pages from a document that holds personal data: keeping the original intact, proving nothing was sent, and what splitting will never do.
Read guide →How to Convert a PDF to Images on Your Own Machine
Rendering PDF pages to JPG or PNG locally, picking a resolution that stays readable, and being honest about what turning a document into pictures destroys.
Read guide →Developer guides
View tools →JSON vs CSV: Differences, Use Cases and Conversion Tips
One holds shape, the other holds a table. Knowing which problem you have decides the format, and decides what breaks when you convert between them.
Read guide →How to Format and Validate JSON Quickly
Reading an unreadable API response, finding the character that actually broke it, and knowing which JSON-like things are not JSON at all.
Read guide →Is It Safe to Decode a JWT Online?
A JWT is readable by anyone who holds it, and pasting a live one into a website hands over a working credential. What that means in practice.
Read guide →What Is Base64, and When Should You Actually Use It?
Base64 turns binary data into text that survives systems built for text. It is not compression and it is not encryption — here is what it is for.
Read guide →What Is a SHA-256 Hash, and What Is It Actually For?
Hashes fingerprint data: same input, same output, and no way back. Where that is useful, where it is misused, and how to check a downloaded file.
Read guide →Are UUIDs Really Unique?
How random a version-4 UUID is, what the collision odds genuinely look like, and the cases where a UUID is the wrong identifier.
Read guide →Unix Timestamps Explained: Seconds, Milliseconds and Time Zones
How epoch time works, how to tell seconds from milliseconds at a glance, and the handful of mistakes that cause almost every date bug.
Read guide →Commas and Quotes in CSV: Why Your File Breaks and How to Fix It
CSV looks trivial until a field contains a comma, a quotation mark or a line break. The rules that actually apply, and how to spot a broken parse.
Read guide →URL Encoding Explained: When to Escape and What Breaks
Why spaces become %20, when a plus sign means a space, and the one rule that prevents most broken links and injected parameters.
Read guide →HEX, RGB and HSL: Which Colour Format to Use and When
The three ways to write a colour on the web, what the numbers mean, and why HSL is the one to reach for when you need to adjust a shade by hand.
Read guide →Regular Expressions for Everyday Tasks
The dozen pieces of regex syntax that cover almost every real job, the traps that cost hours, and a discipline for testing patterns before you trust them.
Read guide →Utility guides
View tools →QR Codes Explained: What to Encode and How to Print Them
What to put in a code, how small it can safely go, why error correction saves a print run, and the mistakes that only show up after ten thousand copies.
Read guide →Percentage Calculations Explained With Simple Examples
The three calculations people actually need, the two that reliably go wrong, and why a rise and a fall of the same percentage never cancel out.
Read guide →Do QR Codes Expire?
Static codes last as long as the thing they point to. Dynamic ones last as long as somebody keeps paying. Know which you have before you print anything.
Read guide →How to Check Where a QR Code Leads
A printed square gives no clue where it points. How to read one from a photo before anything opens it, and what the sticker scams actually look like.
Read guide →Security guides
View tools →Browser-Based Tools and Privacy: What Local Processing Means
What it means for a website to process a file without uploading it, how to check the claim yourself, and where the claim genuinely stops applying.
Read guide →How to Choose a Strong Password
What actually makes a password hard to break, why the old complexity rules were counterproductive, and what to do about the ones you already have.
Read guide →Are Online Password Generators Safe?
The answer turns on one question: does the password exist anywhere other than your own browser? How to check, and how to tell good randomness from bad.
Read guide →What Happens to the Files You Upload to Online Tools?
Where a file goes after you drop it on a converter, what retention policies really promise, and how to tell in under a minute whether anything was sent at all.
Read guide →Text guides
View tools →How Many Words Is a Page?
Word counts for essays, reports and speeches, how long a text takes to read aloud, and why your word processor disagrees with the count you were given.
Read guide →Title Case vs Sentence Case: Which Should You Use?
The two capitalisation styles, the rules inside each, and why most modern product and web writing has shifted towards sentence case.
Read guide →How to Compare Two Versions of a Text
Find what actually changed between two drafts, two config files or two exports, without reading both copies line by line and hoping to spot it.
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