Online Developer Tools

50+ browser-based utilities. No install, no account required to try them. Sign in to sync your data across devices.

Bookmarks

Save and organize your favorite links and developer resources in one place.

Notes

Create and manage notes quickly. Markdown-supported note-taking for developers.

Code Snippet Manager

Save, edit, and copy code snippets with Monaco syntax highlighting, auto-detect language, view and edit modes, and format JSON, SQL, and more. Stored locally in your browser.

Task Manager

Organize daily tasks, set priorities, and track your productivity. A to-do app built for developers.

Email Validator

Verify and validate email addresses with MX record checks and RFC 5322 syntax validation.

Environment Manager

Organize environment variables by project and environment. Encrypted on your device with AES-256-GCM before sync.

JWT Decoder

Decode JSON Web Tokens in the browser: header, payload, exp, iat, and nbf. No server upload; signature not verified.

Certificate / PEM Decoder

Paste an X.509 PEM certificate or PKCS#10 CSR to inspect subject, issuer, validity, serial, SHA-256 fingerprint, and Subject Alternative Names. Runs locally in your browser.

Encryption Playground

AES-GCM encrypt and decrypt in the browser with a raw key (hex or Base64) or a passphrase (PBKDF2-SHA256 + AES-GCM). Outputs a small JSON bundle you can copy and decrypt locally—educational and occasionally practical. Nothing is uploaded.

Password Manager

Securely store and manage passwords with client-side AES-256 encryption. Zero-knowledge vault.

JSON Editor

Format, validate, and edit JSON data with text and tree views. Supports JSONPath queries.

JSON Schema Generator

Generate JSON Schema (Draft 2020-12) and typed models for Python, TypeScript, Go, Rust, Java, C#, Dart, and Swift from sample JSON.

SQL Formatter

Pretty-print SQL in the browser with dialect-aware formatting for MySQL, PostgreSQL, and SQLite.

GraphQL Formatter

Format and minify GraphQL queries, mutations, and subscriptions with Monaco syntax highlighting and a simple query builder. Runs locally in your browser.

Markdown Preview & HTML Converter

Live Markdown renderer with syntax highlighting, HTML export, and HTML → Markdown conversion. Runs entirely in your browser.

Format Converter

Convert between JSON, YAML, TOML, and XML in any direction. All 12 combinations supported. Runs entirely in your browser.

Text Diff Checker

Compare two texts side by side with additions and removals highlighted. Runs entirely in your browser.

Regex Tester

Test JavaScript regular expressions with live match highlighting, flags (g, i, m, s, u), and match counts. Client-side only.

Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 strings instantly, with UTF-8 support. Runs entirely in your browser.

URL Encoder / Decoder

Percent-encode or decode text for query strings and URI components with UTF-8 support.

URL Parser

Parse any URL into protocol, host, path, query parameters, and hash. Runs locally in your browser.

Number Base Converter

Convert integers between number bases 2 through 36 with optional 0x/0b/0o prefixes. Runs entirely in your browser.

Timestamp Converter

Convert Unix seconds or milliseconds, ISO-8601, and date strings. See UTC, local, and relative time with one-click copy.

Unit Converter

Convert between 323 units across 43 scientific and engineering categories including length, mass, pressure, viscosity, thermal, electrical, polymer, and materials science units.

CSV / Excel ↔ JSON Converter

Upload CSV or Excel files and convert to JSON, or export a JSON array of objects back to CSV and XLSX. Dates from Excel become ISO strings. Runs in your browser.

Image to Base64 Converter

Convert images to Data URI or raw Base64 strings instantly. Drops local images and encodes them purely in the browser.

UUID / ULID Generator

Generate UUID v1–v7 or ULIDs with namespace options and bulk copy or download.

Secret / API Key Generator

Generate cryptographically random strings with a configurable alphabet and length. Bulk copy or download; pairs with the UUID generator.

QR Code Generator

Create PNG QR codes from any text or URL with error correction, colors, and margin. Runs entirely in your browser.

.gitignore Generator

Generate .gitignore files instantly for a specific tech stack (Node, Python, macOS, etc.) or combination.

Docker Compose Generator

Pick PostgreSQL, Redis, NGINX, Kafka, Elasticsearch, Prometheus, Grafana, and dozens of other images — get a ready-to-edit docker-compose.yml for local development.

Lorem Ipsum Generator

Generate classical Lorem Ipsum as paragraphs, sentences, words, or lists. Export plain text or HTML.

Mock Data Generator

Build a field schema with dozens of data types, optional blanks, sequences, and export JSON, CSV, SQL, or XML up to thousands of rows — all locally in your browser.

Cron Expression Builder

Build 5-field cron jobs with presets and quick picks, edit raw expressions, read plain-English schedules, and preview next run times.

Hash Generator

Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 digests for text or files with hex output. All hashing runs locally in your browser.

HMAC Generator

Compute HMAC-SHA1, HMAC-SHA256, HMAC-SHA384, and HMAC-SHA512 signatures in hex or Base64 for webhook signing and API integration testing. Runs entirely in your browser.

TOTP / 2FA Code Generator

Paste a Base32 authenticator secret and see the current six-digit RFC 6238 TOTP code refresh every 30 seconds. SHA-1, 30-second step—ideal for testing MFA and sign-in flows. Runs entirely in your browser.

API Client

Test and debug HTTP requests with headers, body, and auth support. A lightweight Postman alternative in your browser.

HTTP Status Codes Reference

Search and browse HTTP status codes (1xx–5xx) with short descriptions and RFC references.

IP / Subnet Calculator

Compute IPv4 and IPv6 CIDR details: netmask, wildcard, broadcast, first and last host, and subnet size. Runs locally in your browser.

User-Agent Parser

Paste a User-Agent string to see browser, OS, engine, device, and CPU breakdown instantly. Runs entirely in your browser.

MIME Type Lookup

Look up MIME types by file extension or filename and copy the result instantly. Runs entirely in your browser.

SQL Client

Connect to PostgreSQL, MySQL, and MariaDB databases from your browser. Run queries, explore schemas, and export results. Credentials encrypted with AES-256 before storage.

NoSQL Explorer

Explore and manage your MongoDB databases directly from your browser.

S3 Drive

Manage AWS S3 and DigitalOcean Spaces buckets. Browse, upload, download, and delete files with end-to-end encrypted credentials.

Color Picker & Converter

Pick colors, convert between HEX, RGB, and HSL, and explore harmonic palettes — shades, complementary, triadic, and more.

WCAG Contrast Checker

Measure WCAG 2.1 contrast between two HEX colors, see AA and AAA pass/fail for normal and large text, and preview typography on the background.

CSS Gradient Builder

Visual CSS gradient builder with angle control, color stops, and one-click CSS copy.

Image Compressor

Compress JPEG, PNG, and WebP images locally in your browser with an adjustable quality slider. No uploads.

SVG Optimizer / Minifier

Paste SVG markup and minify it in the browser with SVGO: drop comments, editor metadata, default attributes, and whitespace—then compare UTF-8 size before and after.