DevToolHQ

Convert Unix timestamps to human-readable dates and vice versa

Countdown timer to a specific Unix timestamp

Generate UUID v4, v7, ULID, and nanoid identifiers

Validate UUID format and detect version

Encode text to Base64 with URL-safe variant option

Decode Base64 strings to plain text

Encode text for safe use in URLs

Decode percent-encoded URL strings

Convert text to hexadecimal representation

Convert hexadecimal strings back to text

Escape HTML entities for safe display

Paste HTML with entities like & < > and instantly decode them back to readable characters. Supports named, decimal, and hex entities.

Decode and inspect JSON Web Tokens with expiry status

Generate SHA-256, SHA-1, and MD5 hashes simultaneously

Generate strong random passwords with customizable options

Test regular expressions with live highlighting and capture groups

Build and explain cron expressions visually

Convert between HEX, RGB, and HSL color formats

Pretty-print and validate JSON data

Compare two texts and highlight differences

Convert CSS properties to Tailwind CSS utility classes

Convert HTML markup to valid JSX for React

Convert SVG markup to React JSX components

Generate TypeScript interfaces from JSON data

Generate formatted markdown tables from a grid or CSV data

Generate placeholder text in paragraphs, sentences, or words

Visual Unix file permission calculator with octal and symbolic notation

Test your typing speed in WPM. Real-time accuracy tracking, multiple passages, instant results.

Detect your public IP address and view geolocation details

Convert Unix timestamps to dates and dates to timestamps — live current time

Complete HTTP status code reference with explanations — 1xx to 5xx

Convert px to rem, em, vw, vh, pt — with custom base font size

Build and explain cron expressions — see next run times in plain English

Generate .gitignore files for Node, Python, React, Go, and 20+ more stacks

Check color contrast ratios for WCAG AA and AAA accessibility compliance

Convert any text to UPPERCASE letters instantly.

Convert any text to lowercase letters instantly.

Capitalize the first letter of each major word (skipping articles and prepositions).

Capitalize the first letter of each sentence.

Convert text to camelCase — the standard for JavaScript variables.

Convert text to PascalCase — the standard for class names.

Convert text to snake_case — the standard for Python and Ruby variables.

Convert text to kebab-case — perfect for URLs and CSS class names.

Convert text to CONSTANT_CASE — all uppercase with underscores.

Convert text to dot.case — words separated by periods.

Convert text to aLtErNaTiNg CaSe — every other letter is capitalized.

Flip the case of every character — uppercase becomes lowercase and vice versa.

Count words, characters, sentences, paragraphs, and estimate reading time.

Remove duplicate lines from your text, keeping only unique entries.

Sort lines of text alphabetically.

Reverse the entire string of text character by character.

Join all lines into a single paragraph by replacing line breaks with spaces.

Collapse multiple spaces and tabs into single spaces and trim each line.

Prepend line numbers (1. 2. 3. ...) to each line of text.

Compare two texts side by side and highlight the differences.

Encode text to Base64 format.

Decode Base64-encoded text back to its original form.

Encode text for safe use in URLs using percent-encoding.

Decode percent-encoded URL strings back to readable text.

Convert special characters to HTML entities for safe embedding in web pages.

Convert HTML entities back to their original characters.

Format and pretty-print JSON with proper indentation.

Minify JSON by removing all whitespace and formatting.

Generate random UUID v4 identifiers.

Convert text to a clean, URL-safe slug.

Generate SHA-256 hash of your text using the Web Crypto API.

Convert between Unix timestamps and human-readable dates.

Decode JSON Web Tokens (JWT) to inspect header and payload.

Strip markdown formatting from ChatGPT, Claude, and other AI outputs to get clean plain text.

Extract all email addresses from text using regex pattern matching.

Extract all URLs (http/https) from text using regex pattern matching.

Extract content from markdown code blocks (``` markers) in AI responses.

Estimate token count and API costs for GPT-4o, Claude Sonnet, and Gemini Flash.

Convert basic Markdown syntax to HTML markup.

Generate lorem ipsum placeholder paragraphs for designs and mockups.

Generate strong, cryptographically secure random passwords of various lengths.

Generate random numbers within a specified range.

Score your headlines on a 1-100 scale with word balance, readability, and actionable suggestions.

Test email subject lines for spam risk, personalization, and engagement with a 1-100 score.

Score any corporate email, LinkedIn post, or press release for buzzword overload (0-100).

Validate JSON with precise error locations

Compress JSON to a single line

Interactive tree view with search

Auto-repair broken JSON from AI outputs

Convert JSON arrays to CSV format

Convert JSON to YAML format

Convert JSON to XML format

Generate Zod schemas from JSON

Generate Go structs from JSON

Generate Python dataclasses from JSON

Convert CSV data to JSON arrays

Convert YAML to JSON format

Compare two JSON documents structurally

Query JSON with JSONPath expressions

Generate JSON Schema from example data

Convert JSON to URL query strings

Convert URL query strings to JSON

Generate Java POJO classes from JSON

Generate Python dataclasses from JSON

Generate C# classes from JSON

Generate Kotlin data classes from JSON

Generate Swift Codable structs from JSON

Generate Rust structs with serde from JSON

Generate Dart classes with fromJson/toJson from JSON

Generate Ruby classes from JSON

Generate PHP classes from JSON

Generate Scala case classes from JSON

Detect exposed API keys, passwords & secrets