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Prime Webkit
The Prime Webkit blog

Guides worth bookmarking.

Practical writing on file optimization, careers, web performance, and building online — from the studio behind the tools.

Image

How to Crop an Image Online (Free, No Upload)

Cropping is the fastest way to improve a photo. Here's how to crop to the right aspect ratio for avatars, thumbnails, and social posts — privately, in your browser.

April 2, 20265 min read
PDF

How to Unlock a PDF (Remove Restrictions You're Allowed to Remove)

The difference between PDF passwords, when you can legitimately remove restrictions, and how to unlock a PDF you own in your browser without uploading it.

March 30, 20265 min read
Career & Business

How to Create a Signature Online (Free Transparent PNG)

Draw or type a signature, export a clean transparent PNG, and drop it into contracts, PDFs, and emails — all in your browser, with nothing uploaded.

March 28, 20265 min read
Career & Business

How to Generate a Business Name That Actually Works

A practical framework for naming a business or brand — what makes a name work, mistakes to avoid, and how to brainstorm dozens of ideas from a few keywords.

March 26, 20265 min read
Text

Case Converter: How to Change Text to Uppercase, Title Case, camelCase and More

A practical guide to text case — when to use Title Case vs Sentence case, what camelCase and snake_case are for, and how to convert between them instantly.

March 25, 20265 min read
Text

What Is Lorem Ipsum? (And How to Generate Placeholder Text)

Where lorem ipsum comes from, why designers use placeholder text instead of real copy, and how to generate exactly the amount you need.

March 24, 20265 min read
Text

How to Turn Text Into Speech (Free, In Your Browser)

Why reading text aloud helps you proofread, learn, and stay accessible — plus how text-to-speech works and how to use it privately without any downloads.

March 22, 20264 min read
Text

How to Remove Line Breaks From Text (The Clean Way)

Text copied from PDFs and emails often arrives with a break on every line. Here's how to remove or normalise line breaks without mangling your paragraphs.

March 22, 20265 min read
Text

How to Compare Two Texts and Spot Every Change

A text diff shows exactly what changed between two versions. Here's how to compare drafts, contracts, and configs — and read the results with confidence.

March 20, 20265 min read
Image

How to Build a Colour Palette (and Pull Colours From Any Image)

Understand HEX, RGB, and HSL, learn how colour harmonies work, and see how to generate a palette or extract one from an image — free and in your browser.

March 19, 20264 min read
Text

How to Create a URL Slug (and Why It Matters for SEO)

A clean URL slug helps SEO, sharing, and usability. Learn the rules for good slugs and how to turn any title into one instantly.

March 18, 20265 min read
Developer

URL Encoding Explained (When and Why to Percent-Encode)

What %20 and %2F actually mean, when you need to encode a URL, and how to encode or decode query strings correctly — with the component vs full-URL distinction.

March 16, 20266 min read
Developer

What Is a UUID? (And How to Generate One Safely)

UUIDs are the unique IDs behind modern software. Learn what they are, why v4 is the one you usually want, and how to generate them securely in bulk.

March 14, 20265 min read
Developer

How to Generate a Hash (SHA-256 and Friends), Explained

What a hash is, why SHA-256 is everywhere, why MD5 is dead, and how to generate a hash from text in your browser for checksums and fingerprints.

March 12, 20265 min read
Developer

How to Decode a JWT (and What Each Part Means)

JSON Web Tokens power modern auth. Learn how to read the header, payload, and claims of a JWT — and why decoding is never the same as verifying.

March 10, 20266 min read
Developer

How to Test a Regular Expression (Without Losing Your Mind)

Regex is powerful and famously fiddly. Learn a practical way to build and test patterns, understand flags, and debug matches in real time.

March 8, 20266 min read
Developer

Unix Timestamp Converter: Epoch Time Made Simple

What a Unix timestamp is, why software stores time as a number, and how to convert between epoch seconds and human dates — in seconds or milliseconds.

March 6, 20265 min read
Image

How to Resize an Image Online Without Losing Quality

Everything you need to know about resizing images the right way: pixels vs. percentage, why aspect ratio matters, and how to resize privately in your browser.

March 4, 20265 min read
Image

PNG to JPG, JPG to WebP: How to Convert Image Formats (and Which to Use)

A plain-English guide to JPG, PNG, and WebP — what each is good at, when to convert between them, and how to do it privately in your browser.

March 1, 20265 min read
PDF

How to Convert a PDF to JPG — Every Page, Free and Private

Turn PDF pages into images for thumbnails, previews, and slides. Here's when to convert PDF to JPG vs PNG, how to keep pages crisp, and how to do it in your browser.

February 25, 20265 min read
PDF

How to Split a PDF: Extract Pages the Easy Way

Whether you need one page or a clean set of separate files, here's how PDF splitting works, when to use it, and how to do it privately in your browser.

February 21, 20265 min read
Developer

How to Create a Strong Password (and Why Length Beats Complexity)

What actually makes a password hard to crack, the myths that waste your time, and how to generate genuinely strong passwords privately in your browser.

February 17, 20265 min read
Text

Word Count, Character Count, and Reading Time — Explained

Why word and character limits exist, how reading time is estimated, and how to track it all live as you write, privately in your browser.

February 13, 20265 min read
Career & Business

How to Create a Professional Invoice (Free Guide for Freelancers & Small Businesses)

What every invoice must include to get paid on time, common mistakes that cause delays, and how to create a clean invoice PDF for free in your browser.

February 9, 20265 min read
Calculators

Unit Conversion Made Simple: Metric, Imperial, and Everything Between

A practical guide to converting length, weight, temperature, and more — the formulas worth knowing, the conversions people get wrong, and a free tool that does it all.

February 5, 20265 min read
Calculators

How to Calculate Your Loan EMI (With Worked Examples)

Understand exactly how a loan or mortgage monthly payment is worked out, what drives the total interest you pay, and how to model it all instantly for free.

February 1, 20266 min read
PDF

How to Convert PDF to Word — Free, and Without Uploading Your Files

A practical guide to converting a PDF into an editable Word document, why most online converters ask you to upload sensitive files, and how to do it privately in your browser.

January 19, 20266 min read
PDF

How to Convert Word to PDF for Free (and Keep Your Formatting Intact)

Why you should send a PDF instead of a .docx, how Word-to-PDF conversion preserves your layout, and how to convert a document in your browser without installing Office.

January 16, 20265 min read
PDF

How to Convert JPG to PDF (and Combine Several Images into One File)

Turn photos and scans into a single, tidy PDF — the right way to submit documents, receipts, and portfolios. Do it in your browser with no upload and no watermark.

January 13, 20265 min read
PDF

How to Merge PDF Files Into One (Free, Private, and In Your Browser)

The clean way to combine multiple PDFs into a single document, control the page order, and do it without uploading confidential files to a third-party server.

January 10, 20265 min read
Image

How to Remove the Background From an Image for Free

A practical guide to cutting out a subject and exporting a clean transparent PNG — what works, what to shoot for, and how to do it privately in your browser.

January 7, 20265 min read
Career & Business

How to Create a QR Code — Links, Wi-Fi, and Contact Cards

A complete guide to making QR codes that actually work: which type to choose, why static beats 'dynamic' for most people, and how to make one free with no tracking.

January 4, 20266 min read
Calculators

How to Calculate Your Exact Age in Years, Months, and Days

Working out an exact age is trickier than it looks, thanks to leap years and uneven months. Here's how age calculation really works and how to get an exact answer instantly.

January 2, 20265 min read
Calculators

How to Calculate Percentages: A Practical Guide With Examples

The four percentage problems that cover almost everything — percent of a number, percent change, and adding or subtracting a percentage — explained with real examples.

December 29, 20255 min read
Career

Building an ATS-Friendly Resume: What Actually Gets You Past the Filter

Most resumes are read by software before a human sees them. Here's what applicant tracking systems look for, the formatting mistakes that get you filtered out, and how to build a clean CV for free.

December 2, 20252 min read
PDF

How to Reduce PDF File Size for Email (Without Losing Readability)

Your PDF is too big to email? Here's why PDFs balloon in size, the fastest ways to shrink them, and how to do it privately without uploading confidential documents.

November 25, 20252 min read
Image

How to Compress Images Without Losing Quality (2025 Guide)

A practical guide to shrinking JPG, PNG, and WebP images for the web — what actually causes quality loss, the right settings to use, and how to do it privately in your browser.

November 18, 20252 min read