Developer Tools

Generate UUID v4 values in your browser with batch size and format options such as uppercase, no hyphens, and braces. Randomness comes from the native crypto API for test data and unique identifiers.

Compare two text blocks locally in your browser and mark added, removed, and unchanged lines. Useful for configs, copy review, and quick code-snippet diffs with instant results.

Build a query string from key/value pairs in your browser and encode special characters. Useful for API debugging, tracking links, and share URL assembly.

Parse a User-Agent string locally to infer browser, operating system, and device type. Useful for access-log triage and client compatibility checks.

Parse a URL into protocol, host, port, path, query, and hash fields, and list each query parameter name and value. Useful for debugging API URLs and share links.

Generate random passwords locally with custom length and character sets. Useful for account setup, staging credentials, and test data. Passwords never leave the page.

Parse raw request or response header text into structured key/value pairs locally. Useful for API debugging, cache policy checks, and CORS header review.

Convert numbers between binary, octal, decimal, and hexadecimal locally in your browser. Useful for embedded debugging, bitwise checks, and address inspection.

Generate Nano IDs in batches locally with custom length and alphabet. Useful for short URL identifiers and front-end object IDs without uploading data.

Generate Chinese or English Lorem Ipsum paragraphs locally with a customizable count. Useful for design mockups, typography tests, and front-end layout previews.

Compute intersection, union, or difference for two text lists locally in your browser. Useful for roster compares, keyword crosses, and everyday data cleanup.

Split a Cookie string into key/value pairs locally and attempt URL decoding. Useful for session debugging, API checks, and field review.

Convert identifiers among camelCase, snake_case, kebab-case, PascalCase, and CONSTANT_CASE instantly.

Convert images or SVG into data: URLs locally for embedding in HTML, CSS, or small resource references. Files are not uploaded.

Split a data: URI locally, identify MIME type and payload, and preview common image or text content. Useful for analyzing inline page resources.

Visually configure Cookie name, value, Path, Domain, HttpOnly, Secure, and SameSite attributes locally and generate a Set-Cookie fragment.

Format compact or single-line SQL into readable indentation locally, with common dialect options. Useful before review and when debugging logged queries.

Minify CSS locally by removing extra whitespace and comments. Useful for quick size cleanup of static snippets before release.

Minify HTML fragments locally by removing extra whitespace and line breaks. Useful for template cleanup and size comparison without uploading markup.

Build, parse, and CRC16-check Modbus RTU and TCP (MBAP) frames in your browser. Covers common function codes FC01–FC16 for coils and registers used in industrial IoT debugging.

Calculate DIP switch ON/OFF patterns for hardware slave addresses such as Modbus devices. Choose 1–8 switches and preview binary masks for field installation and IoT commissioning.

Generate random strings locally in your browser by length and character set, using the Web Crypto random source. Useful for API tokens and filler test values.

Look up file extensions and MIME Content-Type values locally in your browser. Covers common formats for server config, upload checks, and API debugging.

Look up HTTP status codes and keywords locally in your browser. Covers common 1xx–5xx codes with meaning and typical usage notes for API debugging.

Split hostnames from domains or URLs locally in your browser. Identify subdomains, registrable domains, and common public suffixes for CDN, certificate, and security reviews.

Minify multi-line SQL into a compact single line locally in your browser, with an option to strip comments. Useful for log embedding, payload size checks, and transport.

Convert text line endings among LF, CRLF, and CR locally in your browser, and summarize the current mix. Useful for Git, scripts, and cross-platform files.

Convert leading indentation between tabs and spaces locally in your browser, with a configurable space width. Useful when aligning team style or migrating IDE defaults.

Visualize invisible characters locally in your browser, including tabs, newlines, BOM, and zero-width characters. Useful when paste or copy artifacts break parsing.

Parse .env text into a key/value table locally in your browser and export JSON. Sensitive key names such as SECRET, PASSWORD, and TOKEN are masked for safer review.

Generate common barcode formats such as Code128 locally in your browser and export an image. Useful for label samples, inventory tests, and logistics code checks.

Generate a Wi-Fi connection QR code locally from SSID, password, and encryption type. Credentials stay in the browser and are only encoded into the QR payload.

Generate common mock fields such as names and emails locally in your browser and export JSON or other formats. Useful for list placeholders, prototypes, and API stubs.

Fill JSON templates that use double-brace placeholders with mock values such as names, emails, and dates while preserving nested structure. Useful for API and frontend stubs.

Generate a table of contents with anchor links from Markdown headings locally in your browser. Supports slug rules and an option to skip H1. Useful for README and long-form docs.

Strip single-line and block comments from common languages such as JS/TS, Python, CSS, and HTML/XML locally in your browser, and compress leftover blank lines where possible.

Escape multi-line HTML, JSON, or quote-heavy text for languages such as JavaScript, Java, and SQL so you can paste it into string literals without syntax errors.

Normalize messy spreadsheet or API headers—including Chinese labels, symbols, and inconsistent spacing—into snake_case or camelCase identifiers for code and ORM models.

Infer TypeScript interface definitions from JSON in your browser. Nested objects become separate interfaces, with options for the root name, optional fields, readonly, export, and type aliases.

Convert JSON into Go structs with json tags, nested types, and slice handling. Useful for drafting backend models from API responses.

Turn REST-style JSON samples into GraphQL type definitions with Int, Float, String, and Boolean scalars. Helpful when sketching a first schema during API migration.

Parse MySQL, PostgreSQL, or SQLite CREATE TABLE statements and emit matching TypeScript interfaces. Strips comments and common index clauses with regex-based column extraction.

Convert MongoDB shell or Compass extended JSON (ObjectId, ISODate, NumberInt, and similar) into plain JSON for formatting, sharing, and downstream tools.

View JSON and NDJSON logs as a collapsible, syntax-colored tree. Expand or fold nodes to inspect deep structured logs locally in the browser.

Decode Bencode strings used in torrent files and DHT messages (i..e, d..e boundaries) into readable JSON structures in the browser.

Convert cURL commands into JavaScript fetch code. Parses -X, -H, and --data-raw into method, headers, and body, with optional async/await wrapping.

Inspect bcrypt hash strings ($2a$10$...) locally without cracking passwords. Extract version, cost rounds, salt, and digest layout for security reviews.

Decode JWTs locally into readable Header and Payload JSON. Tokens never leave the browser.

Compute safe request rates from quota limits and time windows. Add safety margins to estimate per-request delay and total batch duration without hitting 429 responses.

Estimate compressed transfer size for HTML or JSON text using Shannon entropy heuristics. Compare raw vs gzip and brotli ratios without deploying a server.

Search HTTP status codes from 100 to 511 with plain-language meanings, typical causes, and fix hints. Filter by class and copy individual cards locally.

Diagnose cross-origin issues and generate Access-Control headers for Nginx, Node.js/Express, and Apache. Highlights invalid combinations such as credentials with wildcard origins.

Parse PEM X.509 certificates locally to read validity, subject-related fields, and DER size. Lightweight inspection without full chain trust validation.

Decode JWT structure into formatted Header and Payload JSON with algorithm and expiry hints. Does not verify signatures; all processing stays local.

Clean broken-line SSH public or private keys, detect OpenSSH and PEM forms, and output authorized_keys-ready lines—all locally without uploading secrets.

Batch-generate MAC addresses with chosen case, separator, and optional OUI prefix for ACL samples, IoT tests, and format conversion.

Identify UUID version and variant, validate 32-hex structure, and extract embedded timestamps for V1, V6, and V7—all locally in the browser.

Test JavaScript regular expressions in your browser with native RegExp. Supports flags such as i, g, and m, highlights matches, and shows capture groups with offsets for debugging email, crawler, and validation rules.

Locate invalid JSON error positions in your browser, highlight the character that triggers SyntaxError, and apply heuristic fixes for trailing commas, single quotes, and unquoted keys.

Turn CSV, TSV, or terminal-copied text into aligned ASCII or Markdown tables in your browser, with mixed Chinese and English width handling for README, Slack, and log output.

Edit and preview mixed HTML, CSS, and JavaScript inside an isolated iframe on the page. Useful for validating small frontend snippets without opening a local project.

Generate QR codes locally in your browser with Canvas. Supports L through H error correction for URLs, text, WiFi payloads, and PNG download without uploading content.

Generate Nginx server blocks from form options, including reverse proxy, WebSocket, SSL, Gzip, and basic security headers. Copy or download conf files for static sites and app reverse-proxy starters.

Generate Dockerfiles for Node, Python, Go, and related stacks with optional multi-stage builds, non-root users, timezone packages, and a matching .dockerignore starter.

Select App, Nginx, database, and cache services to generate a local docker-compose.yml with ports and common dependency combinations for dev or demo environments.

Combine operating-system and stack templates in your browser to produce a usable .gitignore for new repositories, covering system junk and common dependency directories.

Fill in the executable path and restart policy to generate systemd Unit and Service files for wrapping local processes as Linux daemons with boot-time startup.

Toggle read, write, and execute bits to convert between octal and symbolic chmod formats, with example commands for scripts, directories, and recursive changes.

Calculate subnet mask, network address, broadcast address, and usable host count from an IP and CIDR prefix for internal segmentation, Docker networks, and routing plans.

Generate bcrypt password hashes and verify plaintext locally in your browser. Adjust rounds to control cost for manual database writes and hash comparison.

Generate RSA public and private keys locally with WebCrypto and export PEM format for signature testing, API key exchange, and local experiments without a server call.

Encode a username and password into a .htpasswd line using bcrypt for Nginx auth_basic and similar HTTP basic authentication setups.

Format and validate /etc/hosts style rules in your browser, check IP validity, and clean blank lines and invalid comments when taking over messy host mappings.

Browse common flags and examples for frequently used Linux commands such as tar, find, and systemctl without SSHing into a server.

Structure raw Whois text in your browser and extract domain, expiry, DNS, and status fields for domain audits, renewal checks, and registration cleanup.

Convert ASCII text and hexadecimal byte streams in your browser with optional separators for packet decoding, protocol debugging, and low-level string comparison.

Generate User-Agent strings for desktop, mobile, and common in-app browsers such as WeChat and QQ in your browser. Useful for compatibility testing, crawler samples, and header debugging.

Identify network card vendors from MAC address prefixes (OUI) locally in your browser. Useful when unknown devices appear in ARP tables or during LAN asset review.

Escape a raw regex pattern for Java, JavaScript, Python, Go, and other source languages in your browser, reducing double-backslash mistakes when embedding patterns in code.

Match log lines against Grok patterns locally in your browser and inspect captured fields. Useful for debugging Logstash and ELK ingestion rules without a full server pipeline.

Practice SET, GET, HGETALL, and other common Redis commands in a browser-local pseudo terminal with in-memory key state. Useful for syntax drills and demos without installing redis-server.

Generate one or many ULIDs with timestamp-first Crockford Base32 encoding for sortable identifiers and database keys.

Connect to ws:// or wss:// endpoints from your browser, send text frames, and review session logs. Useful for backend WebSocket handshake and message debugging without a throwaway client.

Connect to HTTP(S) streaming endpoints with EventSource, listen for Server-Sent Events, and list incoming chunks. Useful for debugging chat-style streaming APIs and backend push feeds.

Test camera and microphone capture, local loopback, manual P2P signaling, ICE state, and real-time WebRTC statistics in your browser.

Check whether a version satisfies SemVer range expressions such as ^ and ~ in your browser. Useful for explaining npm dependency ranges and validating package.json constraints.

Convert cURL commands with headers, bodies, and form data into Python, Go, Node, PHP, Rust, and other request code in your browser. Useful for turning API docs into runnable scripts quickly.

Assemble common Git commands for undo, rebase, stash, and cleanup scenarios with parameters you can copy to the terminal. Useful when rewriting history or handling conflict-related workflows.

Build package.json files from a form with presets for Jest, TypeScript, ESLint, and more in your browser. Useful for bootstrapping new Node projects with common script fields.

Browse common HTMX attributes, triggers, and swap strategies with keyword search, copy visible snippets, and export Markdown in your browser. Useful for quick hx-* lookups without reading the full docs.

Convert docker run commands into docker-compose.yml locally in your browser, recognizing ports, volumes, environment variables, and images. Useful for turning one-off runs into reusable compose files.

Convert Postman Collections into OpenAPI 3 YAML locally in your browser, extracting paths, methods, and basic parameters. Useful for moving collections into Swagger workflows.

Format GraphQL queries and mutations, normalize indentation, perform basic syntax checks, and export a .graphql file locally.

Configure action, ports, and addresses in a form to generate iptables, UFW, or firewalld commands in your browser. Useful for reviewing allow and block rules before running them on a host.

Generate common OpenSSL commands for self-signed certs, CSRs, certificate inspection, and PFX operations in your browser. Useful when you need standard syntax without memorizing long flags.

Build DNS zone files with SOA, $ORIGIN, $TTL, and A, AAAA, CNAME, TXT, and other records in your browser. Useful for preparing zone files for BIND, CoreDNS, and similar servers.

Generate ~/.ssh/config Host blocks from a form with alias, hostname, port, user, identity file, and optional keep-alive or jump host settings. Useful for turning long ssh commands into reusable aliases.

Configure source, destination, and common rsync flags visually to generate incremental sync commands in your browser. Useful for server migrations, backups, and script preparation.

Pick input/output files, video and audio codecs, and quality presets to generate FFmpeg commands for H.264, H.265, VP9, AV1, and more in your browser. Useful when you need a consistent transcode recipe to copy into scripts.

Fill in a service name, ExecStart, and OnCalendar schedule to generate paired .service and .timer unit files in your browser. Useful when replacing handwritten cron jobs with native systemd scheduling.

Test Nginx location modifiers and URI patterns against request paths locally in your browser. Covers exact, prefix, regex, and ^~ cases—useful when debugging routes stolen by the wrong location block.

Fill subject, style, lighting, and negative prompt sections to assemble Stable Diffusion positive and negative prompts in your browser. Useful for reusable image recipes you can copy or export locally.

Describe your scene and pick aspect ratio, model version, stylize, chaos, and other flags to build a Midjourney /imagine command with --ar, --v, and more in your browser. Useful before pasting into Discord.

Fill role, objective, tone, rules, and output format to generate a system prompt you can paste into chatbots or API calls in your browser. Useful for stable personas and boundary instructions.

Pick flowchart, sequence, Gantt, class, or state diagram templates, edit them, and output Mermaid syntax for Markdown docs or export .mmd files in your browser. Useful for README and technical diagrams.

Preview code in adjustable themes, window styles, and shadows, then copy code, copy SVG, or export SVG in your browser. Useful for docs, social posts, or tickets when a screenshot is not ideal.

Enter version, date, and Added/Changed/Deprecated/Removed/Fixed/Security items to generate Keep a Changelog-style Markdown in your browser. Useful for release notes hygiene.

Enter your name, bio, about-me bullets, and GitHub username, then optionally add stats, language, and streak widgets to generate Profile README Markdown in your browser. Useful for username/username showcase repos.

Configure label, message, color, style, and logo to preview and generate Shields.io badge Markdown/URLs in your browser. Useful for README build status, version, or stack badges.

Enter a project name and blurb, toggle Installation, Usage, API, Contributing, and License sections, then generate a structured README.md skeleton in your browser. Useful when bootstrapping repos or npm packages.

Choose MIT, Apache-2.0, GPL, and other common licenses, enter the copyright holder, and generate LICENSE text to save locally in your browser. Not legal advice—verify against official texts.

Encrypt and decrypt locally in your browser with AES, DES, 3DES, Rabbit, multiple block modes, direct keys, PBKDF2, or passphrase modes, outputting Base64 or Hex. Useful for API debugging and learning.

Compute SHA digests and HMAC signatures with Web Crypto in your browser for common SHA algorithms. Useful when debugging payments, webhooks, and request-body signature checks with data kept local.

Paste two text versions side by side and highlight added and removed segments with a diff algorithm in your browser. Useful for configs, scripts, and long text revisions.

Turn short text into FIGlet-style ASCII art banners with selectable fonts in your browser. Useful for CLI splash screens, terminal demos, and plain-text headings.

Convert identifiers in bulk among camelCase, PascalCase, snake_case, and other common styles, including multi-line input, in your browser. Useful when aligning API field names across stacks.

Test regular expressions locally in your browser, highlight matches, and catch compile errors. Useful when debugging email, IP, or custom extractors without pasting unknown patterns blindly.

Batch-generate ULID, Snowflake, and UUID v4 samples in your browser to compare ordering, length, and format—useful when evaluating primary-key strategies for microservices or sharded databases.

Convert numbers between bases 2 and 36 in your browser. Edit one field to sync decimal, hex, binary, octal, and custom-base outputs—handy for protocol fields and non-standard encodings.

Parse URL query strings into key/value pairs and structured JSON locally in your browser. Useful for debugging long GET params, pagination, and signature fields.

Decode JWT header and payload locally in your browser (iat, exp, sub, etc.) without uploading tokens. Signature is not verified—use for inspection only.

Press any key to see key, code, keyCode, which, location, and modifier flags in real time—helpful when wiring keyboard shortcuts in front-end code.

Scan text for API keys, tokens, and passwords locally in your browser. Recognizes common AWS, GitHub, Slack, Stripe, and generic secret patterns.

Detect and mask phones, national IDs, bank cards, emails, IPs, and Chinese names in plain text locally—ideal before sharing logs or documents.

Estimate mortgage or consumer loan payments with equal-payment or equal-principal methods, including interest totals and amortization tables.

Estimate take-home pay from gross monthly salary using common China individual income tax and social insurance ratios, with optional special deductions.

Project compound growth with optional monthly contributions and compounding frequency, plus yearly breakdown—for savings and investment planning.

Animate bubble, selection, insertion, quick, merge, and heap sort while tracking comparisons and swaps—great for learning and demos.

Draw a signature on canvas, adjust stroke width and color, then export PNG or SVG locally—transparent background supported.

Compute return on investment, annualized ROI, monthly profit, and payback months from cost, revenue, and period—quick project or ad spend checks.

Calculate yearly depreciation and book value using straight-line, double-declining balance, or sum-of-years digits—reference for asset planning.

Edit standard five-field cron expressions with live plain-language descriptions, presets, and simulated next run times.

Expand Tailwind CSS class lists into equivalent native CSS declarations for migration, reviews, and learning what utilities actually apply.

Compute VAT amounts from inclusive or exclusive totals at common China rates (13%, 9%, 6%, etc.) with optional batch lines—for pre-invoice checks.

Online metronome from ~30–300 BPM with meter and tone options plus visual beat feedback—for practice, singing, and recording tempo checks.

Fill app name, operator, and collected data types to generate a starter privacy policy you can copy and refine—local draft only, not legal advice.

Define roles and permission items, tick the intersections to build an RBAC permission matrix, and export CSV. Useful when designing access control or documenting permission scope for product and engineering.

Fill in meeting basics, topics with resolutions, and action items to generate structured Markdown minutes. Useful for recurring standups and cross-team decision records.

Set an event name, target datetime, and theme colors, preview the countdown live, and download a standalone HTML page. Useful for launches and event openers.

Drop or select a file to read its magic number, detect the real format, and show a hex dump of the first 256 bytes.

Paste a JWT to decode Header and Payload with colored segments and highlight expiry and other key claims.

Enter a number to see binary, octal, decimal, and hexadecimal results side by side, with animated division-remainder steps. Useful for learning and classroom demos.

Upload audio to decode locally, draw the waveform, show duration, sample rate, and channels, and export a waveform image. Useful for checking recordings and making thumbnails.

Convert amounts between common currencies using built-in reference rates, with a rate table and quick amount presets. Useful for travel budgets and rough cross-border pricing.

Configure method, URL, headers, and body visually, then generate equivalent cURL and JavaScript Fetch snippets in real time.

Enter a hex or decimal TCP flags value to inspect CWR, ECE, URG, ACK, PSH, RST, SYN, and FIN states and meanings interactively.

Interactively demo stack, queue, linked list, and BST insert/remove with visualization and an operation log. Useful for review and interview prep.

Upload audio, select a precise start/end range on the waveform, preview the selection, and export a trimmed WAV. Useful for clips, ringtones, and trimming silence.

Fill a grid so each row and column matches its regex clue. Practice character classes, quantifiers, and groups through puzzles.

Upload multiple SVG icons to merge them into one SVG sprite with symbol reference snippets and download support.

Enter an IP to analyze version (IPv4/IPv6), type (public/private/loopback), binary form, and known public IP ownership hints.

Enter pre-tax monthly salary to estimate pension, medical, unemployment, work-injury, maternity, housing fund deductions, and individual income tax. Includes city presets, housing-fund rates, and special additional deductions, plus take-home pay, yearly totals, and employer cost.

Generate RSA keys, a self-signed CA, server/client certificates, and CSRs locally, and parse PEM. Useful for local HTTPS without installing OpenSSL.

Fill app name, start URL, display mode, and theme color to generate a standard manifest.json for installable PWA basics.

Read screen, language, timezone, User-Agent, Canvas, and related browser environment fields locally to help with compatibility checks and privacy exposure review. Data is not sent outbound by default.