Fast, free tools that run in your browser

Formatting, conversion and analysis utilities for developers, marketers and everyday work. No sign-up, no upload, no waiting.

Nothing is uploaded
No account needed
Instant results

Developer tools

JSON Formatter & Validator

Paste JSON to format, minify or validate it, with the exact line and column of any syntax error. Works offline and never uploads your data.

Unix Timestamp Converter

Convert a Unix timestamp to dates across time zones, or a date back to seconds and milliseconds. The assumed unit is always shown. Runs in your browser.

UUID Generator

Make 1 to 1000 UUIDs locally with the browser CSPRNG, including time-ordered v7 per RFC 9562. Copy the list or download a .txt. Nothing leaves your device.

JWT Decoder

Paste a JSON Web Token to inspect its header and payload, with exp, iat and nbf shown as real dates. UTF-8 safe, so Chinese claims stay readable.

Regex Tester & Regular Expression Validator

Test a regular expression on your own text with live match highlighting, capture groups, flag toggles and a replacement preview. Nothing uploaded.

Hash Generator & Checksum Calculator

Hash text or a file and get MD5, SHA-1, SHA-256, SHA-384 and SHA-512 at once in hex and Base64. Computed locally in your browser, nothing is uploaded.

Text Diff & Line Compare

Compare two texts line by line with unified and side-by-side views, added and removed counts, visible whitespace and a copyable diff. No uploads.

Markdown Viewer & Exporter

Preview Markdown live and export it as PNG, JPG, WebP, SVG, PDF or HTML at any size, with a page margin and a choice of themes like GitHub. No upload.

Base64 Encoder & Decoder

Encode or decode Base64 with Chinese, emoji and accented text handled correctly. Standard, URL-safe and MIME variants, files and data: URLs. No upload.

URL Encoder & Decoder

Percent-encode or decode text and links with encodeURIComponent, encodeURI or form (+) rules. Handles Chinese and emoji and explains bad sequences.

Markdown to HTML Converter

Convert Markdown to clean HTML with tables, task lists and heading ids. Choose how raw HTML is handled, wrap a full document, minify, copy or download.

HTML to Markdown Converter

Turn HTML or text copied from a web page into clean Markdown: headings, lists, links, images, tables and code blocks. Choose the style. Runs in your browser.

SEO & marketing

Meta Tag Generator & SERP Preview

Fill in a form to generate title, description, canonical, Open Graph and Twitter card tags, and preview how Google truncates your snippet.

UTM Link Builder & Campaign URL Generator

Build tagged campaign links with utm_source, utm_medium and utm_campaign, see every parameter decoded side by side, and strip utm_* tags from old links.

Keyword Density Checker & Word Frequency Analysis

Paste text or HTML to count word frequency, phrase density and sentence length, with an honest bigram view for Chinese. Runs locally and uploads nothing.

Everyday utilities

Image Compressor & Resizer

Shrink JPG, PNG and WebP files by adjusting quality and maximum width. Processing stays on your computer, so private images never leave it.

Image Resizer

Resize one or more images to exact pixels or a percentage, with the aspect ratio locked and no surprise re-compression. Runs on your device, no upload.

Image Format Converter

Convert images between PNG, JPG, WebP and AVIF in your browser, keeping the original size. A quality slider plus an honest check of what your browser encodes.

Photo Metadata Viewer & EXIF Checker

Read the EXIF inside a photo: camera, lens, exposure, date and GPS coordinates. Strip that metadata and download a clean copy. Runs offline, no upload.

Strong Password Generator

Generate random passwords with the browser CSPRNG: choose length, character classes and look-alike exclusion, and see the real entropy. Never stored or sent.

QR Code Generator

Make a QR code for a link, phone number, email or any text. Choose error correction, size, margin and colours, then download PNG or SVG. Made on your device.

PDF Merger & Page Extractor

Combine several PDFs into one, reorder files and pages, drop the pages you do not want or extract a selection. Done in your browser, so files are not uploaded.

Word & Character Counter

Count words, characters, sentences, paragraphs and reading time as you type, with correct Chinese and emoji counting and SMS, title and tweet limit checks.

Case Converter

Convert text to upper, lower, title, sentence, camelCase, PascalCase, snake_case, kebab-case and more at once, plus full-width and half-width. No upload.