Blog
Guides and tutorials on QR codes — how they work, how to create them, and how to get the most out of them.
How to Add Page Numbers to a PDF
Insert page numbers into a PDF with your choice of position, font, and starting page — including skipping a cover page — free, in your browser.
How to Decode Base64 Back to Text
Decode Base64 to text online for free, with correct Unicode handling and a clear error for invalid input instead of garbled output.
How to Base64 Encode Text (Without Breaking Unicode)
Encode text to Base64 online for free, with correct handling of Vietnamese, emoji, and other Unicode text — a common failure point in naive implementations.
How to Change Text Case Online — UPPERCASE, Title Case & More
Convert text between UPPERCASE, lowercase, Title Case, Sentence case, and more, without losing line breaks — and what actually separates Title Case from Capitalize Each Word.
How to Check Palindromes and Anagrams Online
Check whether a phrase is a palindrome, or whether two words are anagrams of each other — with options for ignoring case, spaces, and punctuation.
How to Clean Up Messy Text (Extra Spaces, Blank Lines, Tabs)
Fix text that came through with irregular spacing, blank lines, or tabs — from pasting out of a PDF, a webpage, or a spreadsheet — with cleanup options you control individually.
How to Compare Two JSON Objects (Structurally, Not as Text)
Compare two JSON values online for free and see exactly what changed — key order and formatting differences are correctly ignored, unlike a plain text diff.
How to Compare Two Texts and See What Changed
Compare two versions of a document, email, or config file line by line and see exactly what was added or removed — the algorithm behind it, explained simply.
How to Compress an Image Without Losing Too Much Quality
Shrink a JPG, PNG, or WebP file for uploading, emailing, or faster page loads — see the real before-and-after size and pick a quality level that works.
How to Convert Between HEX, RGB, HSL, and HSV Colors
Convert a color between HEX, RGB, HSL, and HSV instantly, with a visual picker — type any format and the others update live, in your browser.
How to Convert CSV to Excel (.xlsx) Online
Turn a CSV export into a real Excel workbook, with quoted fields, embedded commas, and Unicode text parsed correctly — directly in your browser.
How to Convert CSV to PDF (Without Breaking the Table)
Turn a CSV export into a clean, paginated PDF table — with the header repeating on every page and no row cut in half — directly in your browser.
How to Convert HEIC to JPG Online
Turn an iPhone HEIC or HEIF photo into a universally compatible JPG — free, with a quality slider, entirely in your browser.
How to Convert HTML to PDF Safely, With a Live Preview
Paste HTML code and get a clean PDF, with a live preview as you edit and scripts stripped out before anything renders — directly in your browser.
How to Convert an Image to Base64 Online
Turn a JPG, PNG, WebP, GIF, or SVG into a Base64 string or data URL for embedding in code — free, copy or download, nothing uploaded.
How to Convert JPG to PNG Online
Turn a JPG or JPEG into a lossless PNG for editing, sharp graphics, or a tool that requires it — free, directly in your browser, no upload.
How to Convert JPG to WebP Online
Shrink JPG photos into the smaller WebP format for faster-loading pages, with a quality slider and file size shown — free, in your browser.
How to Convert a JSON Array to CSV
Turn a JSON array of objects into a CSV table — with nested objects flattened into columns and commas/quotes handled correctly, not just a naive join.
How to Convert Markdown to HTML (and Back Again)
Convert Markdown to HTML or HTML to Markdown, either direction, with a live preview — supports tables, strikethrough, and task lists.
How to Convert Markdown to PDF (README, Notes, and Docs)
Write or paste Markdown, preview it live, and export a formatted PDF — headings, lists, tables, and code blocks included — directly in your browser.
How to Convert PDF to PowerPoint (PPTX)
Turn a PDF's pages into PowerPoint slides — what actually happens during this conversion, why the slides aren't editable text, and when to use it.
How to Convert PNG to JPG Online
Shrink a PNG down to JPG with a background color for transparent areas and a quality slider you control — free, directly in your browser.
How to Convert PNG to WebP Online
Shrink PNG graphics into WebP while keeping transparency intact — free, with a quality slider, directly in your browser.
How to Convert RTF to PDF Online
Convert an RTF file's text and basic formatting — bold, italic, underline, paragraphs — to PDF, with a clear explanation of what does and doesn't carry over.
How to Convert Text to Speech Online (Free, No Signup)
Have text read aloud using your browser's own built-in voices — useful for proofreading by ear, no account or app required.
How to Convert TXT to PDF (With Vietnamese and Unicode Text)
Turn plain text into a properly formatted PDF, including Vietnamese diacritics and other Unicode characters, without installing anything.
How to Convert a Unix Timestamp to a Date (and Back)
Convert Unix timestamps to local time, UTC, and ISO 8601 — and dates back to timestamps — without ever confusing seconds and milliseconds.
How to Convert WebP to JPG Online
Turn a WebP image into a universally compatible JPG, with a background color for transparency and a quality slider — free, in your browser.
How to Count Characters Online (With or Without Spaces)
Count characters correctly for a tweet, SMS, or meta description limit — including how emoji and UTF-8 byte size actually get counted.
How to Count Words Online (Accurately, Including Vietnamese)
Count words, characters, sentences, and paragraphs correctly — including Vietnamese text, emoji, and messy spacing that trips up simpler word counters.
How to Crop an Image Online
Crop a photo to an exact aspect ratio with drag-and-zoom framing, on desktop or mobile — free, directly in your browser.
How to Decode a JWT (And Why That's Not the Same as Verifying It)
Decode a JWT's header and payload locally in your browser — and understand clearly why decoding a token never proves it's authentic.
How to Decode a QR Code Online (from an Image or Your Camera)
Read a QR code's content by uploading an image or scanning live with your camera — instantly, entirely in your browser, nothing uploaded or recorded.
How to Extract Emails and URLs From a Block of Text
Pull every email address and URL out of a document, transcript, or forwarded thread automatically, with duplicates removed — instead of scanning by eye.
How to Find and Replace Text Online
Find and replace text with live match highlighting, case sensitivity, and whole-word matching — including why whole-word matching needs to be Unicode-aware for Vietnamese text.
How to Find Word Frequency in Text (Most Common Words)
See which words appear most often in a document — useful for spotting overused words in a draft, or getting a quick sense of a document's recurring themes.
How to Format (Pretty-Print) JSON Online
Format and beautify JSON online for free. Pretty-print minified JSON with 2-space, 4-space, or tab indentation, with clear errors when something's invalid.
How to Generate a Favicon (and Full Icon Set) Online
Turn one image into a complete favicon set — favicon.ico, every standard PNG size, an apple-touch-icon, and a web manifest — as one ZIP download.
How to Generate a SHA-256 Hash Online
Generate SHA-256, SHA-384, SHA-512, or SHA-1 hashes using your browser's own Web Crypto API — no server, no library, just the browser's audited implementation.
How to Generate a Strong Password (And What 'Strong' Actually Means)
Generate a strong, random password using real cryptographic randomness — not Math.random() — and understand what the entropy number actually tells you.
How to Generate a URL Slug From a Title (Including Vietnamese)
Turn any title into a clean, URL-safe slug — with correct handling of Vietnamese diacritics, including 'đ,' which isn't just an accented 'd.'
How to Generate Lorem Ipsum Placeholder Text
Generate Lorem Ipsum by words, sentences, or paragraphs, with optional HTML tags — for filling design mockups and testing how a layout handles body text.
How to Generate UUIDs Online (Real Cryptographic Randomness)
Generate random UUID v4 identifiers using your browser's cryptographically secure random number generator — not a predictable Math.random()-based one.
How to Minify JSON Online
Strip whitespace from JSON and see exactly how much smaller it got — a genuine, measured size reduction, not an estimate.
How to Extract Text from a Scanned PDF (OCR, Free, in Your Browser)
Turn a scanned or image-only PDF into copyable, searchable text — supports English and Vietnamese, entirely in your browser.
How to Remove Duplicate Lines From a List
Clean up a mailing list, contact list, or exported data by removing duplicate lines — without losing the original order or the entry you actually want to keep.
How to Remove an Image Background Online (Free, in Your Browser)
Remove the background from a photo using an AI model that runs entirely in your browser — no upload, no signup, transparent PNG in seconds.
How to Remove Line Breaks From Text
Turn multi-line text into one paragraph, with a space, comma, or custom separator between lines — while keeping paragraph structure if you need it.
How to Resize an Image Online
Resize a photo to exact dimensions or a common preset, with the aspect ratio locked automatically — free, directly in your browser.
How to Reverse Text Online — By Character, Word, or Line
Reverse text by character, word order, or line order — with correct handling of emoji, so a multi-part emoji doesn't turn into a different symbol.
How to Rotate and Flip an Image Online
Fix a sideways photo or mirror an image with 90°, 180°, and flip controls — free, with a live preview, directly in your browser.
How to Sort Lines of Text — A-Z, Numeric, and Natural Sort
Sort a list alphabetically, numerically, by length, or with natural sort order (so item2 comes before item10) — without opening a spreadsheet.
How to Test a Regular Expression Online (with Live Highlighting)
Test a regex against sample text with live match highlighting, capture groups, and flag support — entirely in your browser, nothing uploaded.
How to Unlock a Password-Protected PDF (When You Know the Password)
Remove password protection from a PDF you already know the password to — enter it once, download a copy that opens without it, entirely in your browser.
How to URL-Decode a Percent-Encoded String
Decode percent-encoded text back to plain text online for free — malformed sequences handled gracefully instead of crashing.
How to URL-Encode Text (Percent-Encoding Explained)
Percent-encode text for safe use in a URL — spaces, symbols, and Unicode characters handled correctly, the same way a browser encodes them.
Caesar Cipher and Base64: How to Use Them (and Why They're Not Encryption)
Encode and decode text with a Caesar cipher or Base64 — and understand clearly why neither one protects anything sensitive, despite looking like a code.
How to Validate JSON Online (With the Exact Error Location)
Check whether JSON is valid and get a clear error with line and column when it isn't — instead of scanning a wall of text by eye to find one missing comma.
How to View and Remove EXIF Data from Photos
See a photo's hidden metadata — camera model, date taken, GPS location — and strip it all out before sharing, without re-compressing the image.
How to Protect a PDF with a Password
Add a password to a PDF so it can't be opened without it — set it, confirm it, and download the protected file directly in your browser.
How to Reorder PDF Pages Online
Drag pages into the right order, or use the arrow buttons on mobile, and download the rearranged PDF — no software, no upload, done in your browser.
How to Delete Pages from a PDF Online
Remove a blank page, an outdated cover sheet, or a few pages you don't need — select them and download the result, directly in your browser.
How to Rotate a PDF Online for Free
Fix a sideways or upside-down PDF page by page, or rotate the whole document at once, directly in your browser — no software to install, no upload.
How to Add a Watermark to a PDF
Add a text or image watermark to mark a document as a draft, confidential, or branded — with control over opacity, position, and rotation.
How to Sign a PDF Online for Free
Draw, upload, or type a signature and place it on a PDF without printing or scanning — plus what this kind of signature actually is, and isn't.
How to Convert PDF to Excel for Free
Pull tables out of a PDF into a real spreadsheet — how table detection works, when it works well, and how to check the results before trusting them.
How to Convert PDF to Word Without Re-Typing Everything
Get an editable starting point from a PDF's real text — what converts cleanly, what doesn't, and why scanned documents need a different approach entirely.
How to Compress a PDF and Reduce File Size
Why PDFs get large, how compression actually reduces size, and how to pick a compression level without guessing — including the real trade-offs involved.
How to Split a PDF Into Multiple Files
Pull specific pages out of a PDF, or break it apart entirely — with page-range syntax explained and common mistakes to avoid.
How to Merge PDF Files Into One Document
Combine multiple PDFs into a single file, in the exact order you want, directly in your browser — no software, no sign-up.
How to Convert PDF to JPG: 3 Easy Methods
Turn PDF pages into JPG images — convert every page or just the ones you need, right in your browser, with no software to install.
Is It Safe to Use an Online File Converter?
What actually happens to your file when you use an online converter, why some tools upload it and others don't, and how to check which kind you're using.
How to Convert a Resume to PDF
Why PDF is the right format for a resume, how to convert one from Word without breaking the layout, and what to check before you send it.
How to Convert Excel to PDF: A Simple Guide
How to turn a spreadsheet into a clean, readable PDF — including what happens to multiple sheets, charts, and formulas during conversion.
How to Convert Images to PDF (JPG and PNG)
How to combine JPG or PNG images into one PDF — including reordering pages, keeping image quality, and when a PDF beats sending separate photos.
How to Convert Word to PDF Without Losing Formatting
How to turn a Word document into a PDF without your formatting breaking — what actually changes, what stays the same, and how to fix the common problems.
How to Create a QR Code for a Calendar Event
How to turn event details into a scannable calendar QR code with QRivify — including supported fields, time zones, and testing before you print.
How to Create a QR Code for a Google Maps Location
How to turn an address, place, or exact coordinates into a scannable Google Maps QR code with QRivify — including customization, testing, and common mistakes.
How to Create a QR Code for a Link
A step-by-step guide to turning any website URL into a scannable QR code with QRivify — including customization, download formats, and common mistakes to avoid.
How to Create a QR Code for a PDF
How to turn a hosted PDF into a scannable QR code with QRivify — including where to host the file first, link requirements, and testing before you print.
How to Create a QR Code for a Phone Number
How to create a QR code that opens a phone's dialer with a number ready to call, using QRivify — including number formatting, customization, and testing.
How to Create a QR Code for an Email Address
How to create a QR code that opens a pre-filled email draft with QRivify — including the fields it supports, customization, and common mistakes.
How to Create a QR Code for an SMS Message
How to create a QR code that opens a messaging app with a phone number and pre-filled text, using QRivify — including format details, examples, and testing.
How to Create a QR Code from Text
How to turn any block of plain text into a scannable QR code with QRivify — including customization, download formats, length limits, and common mistakes.
How to Create a vCard QR Code
How to turn your contact details into a scannable vCard QR code with QRivify — including supported fields, format details, and testing before you print.
How to Scan a QR Code on iPhone and Android
No separate app needed — here's exactly how to scan a QR code using the built-in camera on iPhone and Android, plus fixes for when scanning doesn't work.
How to Create a Wi-Fi QR Code
Let guests join your Wi-Fi network with a scan instead of typing a password. How Wi-Fi QR codes work, how to create one with QRivify, and how to scan them on iPhone and Android.
QR Code vs Barcode: What Is the Difference?
QR codes and barcodes both encode data for a scanner to read, but they differ in capacity, structure, and use cases. Here's how to tell them apart and when to use each.
How to Create a QR Code for Free
Step-by-step instructions for generating a free, high-quality QR code for a link, Wi-Fi network, contact card, or plain text — no software or sign-up required.
What Is a QR Code and How Does It Work?
A plain-English guide to QR codes — what those black-and-white squares actually are, how they encode data, and why they've become so common.