Free Online Tools · 100% Local Processing

Image conversion · PDF · text tools · encoding · color · calculators · QR code · and more. Files never leave your device — more private, faster.

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🔒 Why we insist on 100% local processing

Privacy:Your files never leave the browser, eliminating leakage risk.
Speed:No upload/download waiting; speed depends on your device.
Low cost:Pure static hosting on Tencent Cloud EdgeOne — zero server load, tools free forever.
Offline:Most tools still work offline once the page loads.

🖼️ Image Tools Format convert / resize / watermark / ICO / filter / collage View all 23 ›

Image Format Converter

Upload an image, choose the target format (PNG/JPEG/WEBP/BMP), and convert & download locally in one click.

Convert PNG to JPG locally — smaller size, no upload.

Convert JPG to PNG locally — lossless, no upload.

Convert PNG to WEBP locally — smaller size, no upload.

Convert WEBP to PNG locally — lossless, no upload.

Convert JPG to WEBP locally — smaller size, no upload.

Convert WEBP to JPG locally — no upload.

Convert PNG to lossless BMP locally — no upload.

Convert JPG to lossless BMP locally — no upload.

Convert BMP to PNG locally — lossless, no upload.

Convert GIF to a static PNG locally — no upload.

Resize images by ratio, width, or custom dimensions locally and download.

Image Watermark

Upload an image, add a text or image watermark, adjust opacity & position, export locally.

Image Compressor

Compress images locally, adjust quality/width, show savings and download.

Crop images by selecting a region locally, ratio & batch supported.

Image Rotate / Flip

Rotate images any angle / 90° multiples locally, mirror & batch.

Convert an image to a multi-size .ico favicon locally.

Image to Base64

Convert images to/from Base64 locally, copy Data URI or restore.

Apply grayscale/retro/invert filters locally and download.

Join multiple images horizontally/vertically/grid locally.

EXIF Viewer / Stripper

Read photo EXIF locally and strip metadata before re-download.

Image Color Extractor

Extract a main-color palette from an image locally, copy HEX.

Add border and rounded corners to an image locally, preview and download.

📄 Document / PDF PDF convert / merge / watermark / compress / rotate View all 16 ›

Upload a PDF, render each page to an image locally and download — no upload.

Select multiple PDFs and merge them into one file locally.

Upload a PDF, split by page or range locally, download as ZIP.

Upload a PDF, tile a text watermark locally and download.

Render Word (.docx) to PDF locally and download — Chinese text intact.

Render each Excel sheet to PDF locally and download.

PPT Text Extractor

Unpack PPT locally, extract text & notes per slide, export as text.

PDF Page Numbers

Add page numbers to every PDF page locally and download.

Merge multiple images into one PDF locally and download.

Compress PDF by lowering image quality locally, show savings, batch.

Rotate PDF page orientation locally and download.

PDF Text Extractor

Extract PDF text locally with pdf.js, copy or download .txt.

PDF Delete Pages

Delete specified PDF pages locally (ranges supported), keep the rest.

PDF Reorder Pages

Reorder PDF pages in a custom sequence locally and download.

PDF Extract Pages

Extract specified pages/ranges into a new PDF locally, drop the rest.

Markdown to PDF

Render Markdown to PDF locally and download — Chinese text intact.

🧮 Calculators Scientific / mortgage / tax / compound / units View all 14 ›

Scientific Calculator

Local scientific calculation with functions and constants — works offline.

Mortgage Calculator

Compute mortgage monthly payment, total interest and repayment (equal installment).

Percentage Calculator

Compute percentages, ratios and changes locally.

Convert length, weight and area units locally.

Date Calculator

Compute date difference and date +/- days locally.

Compute BMI and body-type reference from height & weight.

Compute tip and per-person amount locally, multi-person split.

Compute exact age and days since birth locally.

Income Tax Calculator

Compute income tax and take-home pay locally by progressive rates.

Compound Interest Calculator

Compute maturity and total interest by compounding frequency.

Salary Converter

Convert between hourly/daily/monthly/yearly wage locally, set workdays & hours.

Timezone Converter

Convert one timezone to many world zones locally with Intl — offline.

Mortgage Calculator

Compute mortgage monthly payment and total interest locally.

Discount / VAT Calculator

Compute discounted price or VAT-inclusive/exclusive amounts locally.

🎨 Color & Design Color picker / palette / contrast / gradient View all 6 ›

Color Design Toolkit

Generate harmonious palettes, check contrast, pick colors from images, make gradients.

Color Code Converter

Convert HEX/RGB/HSL in real time locally and copy.

Color Palette Generator

Generate harmonious palettes from a base color locally.

Contrast Checker

Compute foreground/background contrast and check WCAG AA/AAA.

Color Blindness Simulator

Simulate red/green/blue color blindness locally — preview colors or an uploaded image.

Gradient Generator + Contrast Check

Generate a CSS gradient and check WCAG contrast locally.

🛠️ Utilities QR code / random / pomodoro / password / timer View all 12 ›

QR Code Generator

Enter text/URL, generate a QR code locally and download PNG.

Random Decision

Draw randomly from options, or flip a coin for two choices.

Webpage Screenshot

Capture a webpage screenshot (limited by CORS; planned).

Password Generator

Generate strong passwords locally with crypto randomness, configurable.

Countdown / Stopwatch

Local countdown & stopwatch with custom duration and controls.

Random Number Generator

Generate range/count controlled random integers locally, dedupe & sort.

QR Code Decoder

Recognize a QR image locally and extract URL/text.

Local pomodoro cycles, custom focus/break duration.

Password Strength Checker

Evaluate password strength and checks locally, estimate entropy.

WiFi QR Code Generator

Encode WiFi name/password into a QR code locally; scan to connect.

Stopwatch / Timer

Local stopwatch with start/pause/lap/reset, works offline.

Show multiple time zones at once locally with Intl — offline.

📝 Text Tools Word count / case / sort / diff / find-replace / TTS View all 11 ›

Paste text, count words, characters, lines and paragraphs locally.

Convert English case and full/half-width locally.

Text Sort & Dedupe

Sort lines, dedupe, remove blank lines and count lines locally.

Compare two texts line by line locally, highlight additions & deletions.

Batch find & replace text locally, case & regex supported.

Read text aloud locally with browser TTS, adjustable speed.

HTML Entity Encode / Decode

Convert text and HTML entities locally, prevent XSS & garble.

Markdown Preview

Render Markdown to HTML locally in real time, copy the result.

Lorem Ipsum Generator

Generate Lorem Ipsum of chosen paragraphs locally.

Word Frequency Counter

Count word/character frequency locally, sort and export results.

Text Dedupe / Sort / Count

Dedupe, sort and count lines locally, then copy or download.

💻 Encoding / Dev JSON / Base64 / URL / timestamp / hash / UUID / regex / base View all 17 ›

JSON Formatter / Validator

Format, minify and validate JSON locally, with error line location.

Base64 Encode / Decode

Encode/decode text & images to Base64 locally, Chinese supported.

URL Encode / Decode

Percent-encode and decode URLs/text locally.

Timestamp Converter

Convert between timestamp (sec/ms) and date-time locally.

Hash Calculator

Compute MD5/SHA1/SHA256/SHA512 digests locally.

Generate batch UUID v4 locally with crypto randomness.

Test regex match/replace locally, highlight hits.

Convert between binary/octal/decimal/hex locally, big int.

Convert numeric amounts to Chinese capital locally, copy-ready.

Decode the three JWT parts locally and pretty-print.

Parse cron meaning and predict next runs locally.

CSV ↔ JSON Converter

Convert CSV and JSON both ways locally, multiple delimiters.

AES Text Encrypt / Decrypt

Encrypt/decrypt text locally with AES-GCM, passphrase stays local.

Morse Code Encode / Decode

Convert text and Morse code both ways locally, common characters supported.

URL Parser / Builder

Split a URL into parts and parse query params locally, then rebuild.

XML Formatter / Validator

Format and validate XML locally, indent & locate errors.

HTML Live Preview

Render HTML snippets live in a sandboxed iframe locally for debugging.