Useful tools, running entirely in your browser

Simple tools. Right in your browser.

Free forever
Runs locally
No login
No interruptions

170 tools available, with more on the way.

Code & Development

41 tools

Security Headers Generator (CSP)

Build a Content-Security-Policy and the other security response headers, check them for mistakes, and export them for nginx, Cloudflare Pages or Apache.

Open Tool

Sorting Algorithm Visualizer

Watch bubble, selection, insertion, shell, merge, quick, heap, counting and radix sort run step by step with live comparison and swap counters.

Open Tool

CSS Transform Generator

Compose translate, rotate, scale, skew and 3D transforms visually with a live preview, then copy the CSS, matrix form, or Tailwind value.

Open Tool

Nginx Config Generator

Generate nginx reverse proxy, static site, PHP-FPM, and HTTPS server configs with upstreams and rate limits — all locally.

Open Tool

Semver Range Checker

Check which versions satisfy an npm semver range, right in your browser.

Open Tool

Dockerfile Generator

Generate multi-stage Dockerfiles with a .dockerignore snippet locally in your browser.

Open Tool

License Generator

Generate MIT, Apache-2.0, GPL and other open-source LICENSE texts with file headers, locally in your browser.

Open Tool

CSS Specificity Calculator

Score CSS selectors, compare which rule wins, and see how each part of a selector adds to its specificity.

Open Tool

CSS Filter Generator

Tune CSS filter functions such as blur, brightness, contrast, saturation, hue-rotate, sepia and drop-shadow with a live preview, then copy the CSS or Tailwind output.

Open Tool

robots.txt Generator

Build and validate robots.txt rules with live preview, entirely in your browser.

Open Tool

JSON to SQL Generator

Generate INSERT statements from JSON arrays locally in your browser.

Open Tool

Border Radius Generator

Preview and fine-tune CSS border-radius for one or four corners, then copy CSS or Tailwind classes.

Open Tool

Box Shadow Generator

Design layered CSS box-shadows with a live preview, presets, and CSS or Tailwind export.

Open Tool

CSS Grid Generator

Design CSS grid layouts visually: columns, rows, gaps, and alignment with live preview and CSS or Tailwind export.

Open Tool

cURL Converter

Convert curl commands to fetch, axios, Python requests, Go, or a normalized curl — parsed locally.

Open Tool

Docker Run ↔ Compose

Convert docker run commands to docker-compose.yml and back, with named-volume detection — all local.

Open Tool

Gradient Generator

Design CSS gradients with draggable color stops and export CSS, Tailwind, and config.

Open Tool

JSON / TypeScript Converter

Convert between JSON and TypeScript with interface/type generation and type inference.

Open Tool

Query String Converter

Convert URL query parameters and flat JSON objects in either direction while preserving repeated values.

Open Tool

HTTP Status Codes

Look up HTTP response status codes with plain-language explanations, search, and category filters.

Open Tool

MIME Types Lookup

Search MIME types by extension or content type and browse common web file formats.

Open Tool

Chmod Calculator

Compute Unix file permissions from checkboxes or octal values, including setuid, setgid, and sticky bits.

Open Tool

CSS Unit Converter

Convert between px, rem, vw and vh with a configurable root font size and viewport, in single or batch mode.

Open Tool

CSS Animation Generator

Design fade, slide, scale, rotate, bounce and shake animations and export CSS keyframes with an editable easing curve.

Open Tool

Cubic Bezier Editor

Shape cubic-bezier timing functions by dragging control points, pick templates, preview motion, and copy the CSS.

Open Tool

SVG Editor

Draw and edit vector SVG graphics in the browser, then optimize, compress or export them as PNG icons.

Open Tool

Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal (2–36) locally in your browser.

Open Tool

Cron Expression Parser

Parse cron schedules, explain them naturally, and preview upcoming runs locally.

Open Tool

JSON to Python Dict

Convert JSON into a Python dict literal with True, False, and None.

Open Tool

JSON to Java Class

Generate Java classes with nested static classes and List fields from JSON.

Open Tool

JSON to Go Struct

Generate Go structs with JSON tags and inferred field types from JSON.

Open Tool

JWT Inspector and Generator

Inspect JWTs locally or generate test tokens with an HMAC secret.

Open Tool

Regex Tester

Test regular expressions, read them token by token, and get Python, Java, Go, and PHP equivalents.

Open Tool

Template Fill & Batch Generator

Fill template variables from JSON or CSV, generate a result per template and data row, highlight variables, and export files or a zip.

Open Tool

SVG Badge & Placeholder

Create Shields-style SVG badges or placeholder images locally and export them as SVG or PNG.

Open Tool

.gitignore Generator

Generate a .gitignore by picking templates for languages, frameworks, editors, tools, and operating systems, with search and custom rules.

Open Tool

SQL Formatter

Format and minify SQL queries locally with common database dialects.

Open Tool

Open Graph Card Generator

Preview link cards for Facebook, X, LinkedIn, and Slack, then copy Open Graph and Twitter meta tags for HTML, Next.js, or Nuxt.

Open Tool

Flexbox Generator

Tune flex direction, wrap, justify-content, align-items, and gap with a live preview, then copy CSS or Tailwind classes.

Open Tool

CSS Clip-path Generator

Shape circles, ellipses, insets, and polygons by dragging points, with presets and instant clip-path CSS output.

Open Tool

Font Preview

Compare font stacks and local fonts with adjustable size, weight, line height, and letter spacing on your own text.

Open Tool

Crypto & Security

8 tools

Key Format Converter

Convert keys between PEM, JWK/JWKS and OpenSSH formats, and read SHA-256, MD5 and JWK thumbprint fingerprints — all in your browser.

Open Tool

AWS SigV4 Signature Generator

Compute AWS Signature Version 4 in your browser: canonical request, string to sign, signing key chain, Authorization header and presigned URL.

Open Tool

X.509 Certificate Decoder

Inspect PEM or DER certificates: subject, issuer, validity, SANs, key usage and fingerprints.

Open Tool

AES Encrypt / Decrypt

Encrypt and decrypt text or files with AES-256-GCM and a passphrase, and generate random salts and IVs locally.

Open Tool

XOR Encrypt / Decrypt

Obfuscate text or files with a simple XOR cipher and a key, entirely in your browser.

Open Tool

RSA Key Generator

Generate RSA key pairs (2048-4096 bits) and export them as PEM or JWK locally.

Open Tool

HMAC Generator

Compute HMAC signatures with SHA-1/256/384/512 in hex or base64 output.

Open Tool

Bcrypt Hash

Hash passwords with bcrypt and verify existing hashes at adjustable cost rounds.

Open Tool

Network

5 tools

HAR Analyzer

Open a .har export to find slow, oversized or failed requests, with a per-request waterfall and safe exports.

Open Tool

IP Subnet Calculator

Calculate IPv4 CIDR details: netmask, broadcast, host range, and usable addresses.

Open Tool

URL Parser

Break any URL into protocol, host, path, hash, and a decoded query parameter table.

Open Tool

Port Lookup

Search common TCP/UDP ports by number, service name, or category.

Open Tool

User-Agent Parser

Parse any user-agent string into browser, engine, OS, and device details.

Open Tool

Text

28 tools

HTML to Markdown Converter

Convert HTML into clean GitHub-flavored Markdown — headings, lists, tables, code blocks, links and images.

Open Tool

Text Truncator

Cut text down to a limit by characters, UTF-8 bytes, words or lines, keep the head, tail or middle, and add an ellipsis.

Open Tool

Line Filter

Keep or remove lines by keyword or regex: match any or all patterns, ignore case, and see how many lines remain.

Open Tool

Word Cloud Generator

Turn text or weighted word lists into a downloadable word cloud, with Chinese segmentation, shape and image masks. All local.

Open Tool

Subtitle Converter & Editor

Convert SRT, WebVTT, ASS, SSA, MicroDVD, and SAMI subtitles, create them from text, shift or resync timing, edit cues, and preview — all locally.

Open Tool

Lorem Ipsum Generator

Generate Latin or Chinese placeholder text by words, sentences, or paragraphs locally.

Open Tool

Slug Generator

Turn titles into clean URL slugs with custom separators, accent transliteration, and length limits.

Open Tool

List Shuffler

Shuffle lines, draw random samples, pick winners, or split lists into balanced groups locally.

Open Tool

Email Normalizer

Normalize email addresses locally: Gmail dots and aliases, plus tags, domains, and duplicate detection.

Open Tool

Text to Speech

Read text aloud locally, adjust speed and pitch, choose a voice, play segments with highlighting, and record audio.

Open Tool

Newline and Line Converter

Convert CRLF and LF line endings, clean lines, add line numbers, sort, join with spaces or commas, and reveal invisible characters locally.

Open Tool

Text Escape and Unescape

Escape and decode HTML, XML, JavaScript, JSON, URL, SQL, Unicode, and Base64 text, including batch conversion, locally.

Open Tool

Find and Replace

Find and replace text with literal rules, regular expressions, batch replacement, and multiple rule sets.

Open Tool

Text Case Converter

Convert text between uppercase, lowercase, capitalized, camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE.

Open Tool

Mojibake Fixer

Repair garbled text and convert between UTF-8, GBK, Big5, Shift-JIS, and more — all locally.

Open Tool

Text Deduplicator

Remove duplicate lines or words locally in your browser, keep first or last occurrence, and view duplicate counts.

Open Tool

Text Sorter

Sort lines alphabetically, by pinyin, number, length, random order, or custom priority rules, ascending or descending.

Open Tool

Text Obfuscator

Insert, detect, remove, visualize, and decode zero-width characters, hide text, and export results locally.

Open Tool

Chinese Converter

Convert between simplified and traditional Chinese, including Taiwan and Hong Kong regional word usage, locally in your browser.

Open Tool

Chinese Pinyin Converter

Convert Chinese characters to pinyin with tone marks, numeric tones, or no tones, extract initials, customize separators, and batch convert files locally.

Open Tool

Text Splitter

Split text by characters, lines, commas, spaces, regular expressions, or fixed length, then view it as an array or table.

Open Tool

Text Statistics

Count characters, Chinese characters, English words, lines, paragraphs, and estimate reading time locally in your browser.

Open Tool

Markdown Editor

Write, edit, and preview Markdown with live rendering, tables, task lists, math, diagrams, and highlighted code blocks.

Open Tool

Text Extractor

Paste any text to extract URLs, image addresses, emails, phone numbers, numbers, Chinese, English, IPs, dates, colors, and hashtags.

Open Tool

Text Masker

Anonymize text by masking phone numbers, ID cards, bank cards, emails, and IP addresses locally.

Open Tool

Sensitive Word Checker

Scan text against a local sensitive-word list, highlight matches by category, mask or replace them, and export findings as CSV, JSON, or TXT.

Open Tool

Text Diff

Compare text by line or character, highlight changes, and download unified diffs locally.

Open Tool

Speech to Text

Dictate text in the browser with live transcription in Chinese, English, and more, then copy or download the result.

Open Tool

Encoding & Conversion

10 tools

Full-width & Half-width Converter

Convert between full-width and half-width characters in your browser.

Open Tool

NATO Phonetic Alphabet Converter

Spell text with NATO code words (Alfa, Bravo, Charlie) and decode them back, with aviation digit pronunciation.

Open Tool

Base32 Base58 Codec

Encode and decode Base32, Base32Hex, and Base58 text locally in your browser.

Open Tool

Morse Code Converter

Convert text to Morse code and back, then play the signal aloud.

Open Tool

Basic Auth Generator

Create HTTP Basic Authorization headers and curl commands from a username and password.

Open Tool

Text to Binary Converter

Convert text to binary, octal, decimal, or hexadecimal byte codes and back, with full UTF-8 support.

Open Tool

QR Code Generator and Scanner

Generate QR codes or scan them from images entirely in your browser.

Open Tool

Barcode Generator

Generate CODE39, EAN-13, UPC-A, and EAN-8 barcodes locally and download them as PNG.

Open Tool

Base64 Encoder and Decoder

Encode and decode UTF-8 text, files, and Data URLs.

Open Tool

URL Encoder and Decoder

Encode and decode URLs, query parameters, and form text.

Open Tool

Date & Identifiers

6 tools

iCalendar (.ics) Generator

Create calendar event files (.ics) with reminders and repeat rules, then download, copy, or add straight to Google Calendar — all in your browser.

Open Tool

Chinese Lunar Calendar Converter

Convert dates between the Gregorian and Chinese lunar calendars from 1900 to 2100, with leap months, ganzhi years, and zodiac animals — all locally.

Open Tool

Unix Timestamp Converter

Convert between Unix timestamps, local dates, and UTC.

Open Tool

World Clock and Time Zone Converter

Compare current time across cities and convert any moment between time zones.

Open Tool

Age & Zodiac Calculator

Exact age in years, months, and days plus Chinese zodiac, stem-branch year, star sign, and day milestones.

Open Tool

Date Calculator

Find how many days, weekdays, weeks, months, or years are between two dates, and add or subtract time from any date.

Open Tool

Files & Checksums

27 tools

File Type Detector

Detect a file's real type from its magic bytes, compare it with the extension, and inspect the header bytes — all locally in your browser.

Open Tool

Video to GIF

Trim a video clip and convert it to a looping GIF with palette control, dithering, and reverse playback — all locally.

Open Tool

Image Steganography

Hide text or files in the least significant bits of a PNG, with optional password encryption, and extract them back — all locally.

Open Tool

Screenshot Mockup Generator

Wrap screenshots in browser, MacBook, iPhone, iPad, or Android frames with custom backgrounds, then download the mockup locally.

Open Tool

Image Diff

Compare two images pixel by pixel locally in your browser: highlight differences, a difference heatmap, tolerance control, and stats.

Open Tool

PDF Toolkit

Merge, split, and compress PDF files entirely in your browser.

Open Tool

Images to PDF

Combine JPG, PNG, WebP, GIF, BMP, or AVIF images into one PDF with page sizes, margins, and N-up grids, all locally.

Open Tool

Audio Recorder & Editor

Record from your microphone or import audio, then trim, fade, equalize, compress, change speed, and export WAV or MP3, all locally.

Open Tool

Erase passers-by, objects, and clutter from photos locally in your browser. Brush over what should go or click an object to select it, and an on-device inpainting model rebuilds the background behind it.

Open Tool

Image to Text (OCR)

Extract text from images with on-device OCR. English and Chinese, batch support, nothing uploaded.

Open Tool

Image Info Viewer

Inspect any image locally: file name, type, size, dimensions, transparency, animation, color mode, DPI, EXIF, and hash. Runs entirely in your browser.

Open Tool

EXIF Remover

Strip EXIF metadata from images locally: GPS, device info, capture time, and more. Keep orientation and export a cleaned batch as ZIP.

Open Tool

Image Background Remover

Remove image backgrounds locally in your browser: solid color cutout, magic-wand selection, click-to-pick objects, and AI matting. Cut out or keep only what you picked, then export transparent PNG or swap in a color or photo background.

Open Tool

Image Redaction

Hide sensitive parts of an image locally: drag a box or paint over faces, ID numbers, and addresses with mosaic, blur, or a solid bar, and export a flattened copy without metadata.

Open Tool

Image Slicer

Slice images into a grid of tiles: 2x2, 3x3, 4x4, or custom rows and columns. Sequential naming and ZIP export, all local in your browser.

Open Tool

Image Stitch

Stitch images into one: horizontal and vertical strips, square grids, nine-grid collages, and free templates with gap, padding, background color, rounded corners, all local in your browser.

Open Tool

Image Watermark

Add text or logo watermarks to images locally in your browser. Single or tiled placement, diagonal traceability watermarks, opacity, rotation, size, position, and batch processing.

Open Tool

Image Cropper

Crop, rotate, and export images to exact sizes locally in your browser. Batch crop, circular avatars, ID photos, and social media presets.

Open Tool

Image Compressor

Batch-compress JPEG, PNG, WebP, GIF, and BMP images locally in your browser with quality, resizing, and format conversion controls.

Open Tool

Image Color Extractor & Picker

Pick colors from any image with a magnifier, copy HEX, RGB, and HSL, extract the dominant palette, and export ASE, JSON, CSS, GIMP, or PNG.

Open Tool

Image to ASCII Art

Turn any image into monochrome ASCII art in your browser, with character presets, a custom ramp, and brightness and contrast controls.

Open Tool

Image to Pixel Art

Pixelate images locally, adjust pixel size, limit colors, generate a palette, show a grid, and export PNG or color tables.

Open Tool

Favicon Generator

Turn one image into a full favicon set: ICO, PNG, SVG, Apple touch and Android icons plus a PWA manifest.

Open Tool

Hash Calculator and File Checksum

Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 for text and files, and compare checksums.

Open Tool

Batch Rename Files

Rename many files at once with find and replace, prefixes, cleanup, and numbering, then download a ZIP or rename in place.

Open Tool

ZIP Archive Tool

Open a ZIP to browse and preview entries, download selected files, or pack files and folders into a new ZIP, all locally.

Open Tool

Pixel GIF Maker

Draw pixel art frames and animate them into a GIF locally, then download it.

Open Tool

Data

11 tools

Excel to CSV / JSON

Turn an .xlsx workbook into CSV or JSON locally, with a sheet picker and real date values.

Open Tool

SQLite Viewer

Open a SQLite database file to browse tables, page through rows, and run read-only SELECT queries, then export results.

Open Tool

JSON Diff

Compare two JSON documents semantically — key order independent, with array matching and RFC 6902 Patch export. All local.

Open Tool

Table Editor

Import CSV, TSV, Markdown, or JSON tables, edit cells with sort, find and replace, undo, and export to XLSX, CSV, TSV, Markdown, or JSON locally.

Open Tool

JSON Schema Generator

Generate JSON Schema from sample data or sample JSON from a schema, with type inference and options.

Open Tool

JSON Formatter

Format, minify, repair and validate JSON data.

Open Tool

HTML & CSS Formatter

Format or minify HTML and CSS locally with safe, lightweight parsing.

Open Tool

JSON to JavaScript Object

Convert JSON into a JavaScript object literal with identifier-friendly keys.

Open Tool

Data Converter

Convert .env, JSON, YAML, TOML, or XML entirely in your browser.

Open Tool

CSV / JSON Converter

Convert tabular CSV data and JSON arrays locally with type detection and escaping.

Open Tool

Mock Data Generator

Generate realistic fake data locally: names, phones, emails, IDs, addresses, IPs and more, exported as JSON, CSV, SQL or NDJSON.

Open Tool

Utilities

34 tools