Free Developer Tools Online
Free developer tools online are the quick utilities programmers reach for dozens of times a day: pasting messy JSON to format and validate it, encoding a string to Base64, generating a strong password, or checking what a color looks like. This collection puts those utilities one click away, with no sign-up and no clutter.
Everything sensitive here runs entirely in your browser. That matters for developer tools more than anywhere else: pasting an API key, a token, or production data into a random website is a real security risk. These tools never send your input to a server — what you paste stays on your machine.
Alongside the code-focused tools you'll find everyday text utilities developers use constantly: word counter, case converter, URL and HTML encoders, Unix timestamp converter, lorem ipsum generator, slug generator, and Markdown converters. Simple jobs, done instantly, without opening an IDE.
Browse tools
All Developer Tools
14 free developer tools — no sign-up, no installs, most run entirely in your browser.
JSON Formatter
Format, validate, and minify JSON.
Password Generator
Create strong, random passwords.
Word Counter
Count words, characters, and reading time.
Case Converter
Convert text between cases in one click.
Color Picker
Pick colors and copy HEX, RGB, HSL codes.
Unit Converter
Convert length, weight, temperature, and data.
Base64 Encoder & Decoder
Encode text to Base64, decode it back, or turn files into data URIs.
URL Encoder & Decoder
Encode or decode URLs and query strings in two modes.
HTML Encoder & Decoder
Convert HTML to entities and entities back to readable text.
Unix Timestamp Converter
Turn epoch timestamps into dates and dates into timestamps.
Lorem Ipsum Generator
Placeholder text by paragraphs, sentences, or words — one click.
URL Slug Generator
Turn any headline into a clean, SEO-friendly URL slug.
Markdown to HTML Converter
Write Markdown, get clean HTML with a live preview.
HTML to Markdown Converter
Turn messy HTML into clean, readable Markdown.
Buying guide
How to choose the right developer tool
Developer tools are single-purpose by design. Identify your data type first, then pick the tool.
Validating vs. formatting JSON
The JSON formatter does both: it validates your JSON and shows you exactly where the error is, then pretty-prints it so the structure is readable. Always validate before blaming your code.
Encoding is not encryption
Base64, URL encoding, and HTML encoding change how data looks, not who can read it. They are safe for formatting and transport — never use them to 'protect' secrets or passwords.
Generate passwords, don't invent them
The password generator creates long, random passwords that humans can't guess. Pair it with a password manager — a generated password you can't remember is useless without one.
Timestamps and timezones
The Unix timestamp converter turns epoch seconds into a readable date and back. Remember that timestamps are always in UTC — your local time display depends on your device's timezone setting.
Questions
Frequently asked questions
Quick answers about these developer tools.
Yes. Every developer tool on this page is free with no sign-up and no usage limits. They run in your browser, so there is nothing to pay for and no account to create.
These tools process everything locally in your browser and never send your input to a server, so pasting sensitive data is far safer here than on a typical online tool. Still, avoid pasting live production secrets anywhere you don't fully trust, as a habit.
Base64 encoding just represents data in a different format — anyone can decode it instantly. Encryption uses a key to actually hide the data. Use encoding for formatting and transport, encryption for secrecy.
The slug generator lowercases your title, replaces spaces and special characters with hyphens, and strips anything that doesn't belong in a URL. The result works in web addresses, file names, and IDs.
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