Developer Tools

Format, encode and generate — JSON, Base64, hashes and more.

JSON FormatterNew

Format, validate and minify JSON with helpful errors.

Open
Base64 Encode / DecodeNew

Encode text to Base64 or decode Base64 back to text.

Open
URL Encoder / DecoderNew

Percent-encode or decode URLs and query strings.

Open
Hash GeneratorNew

Generate SHA-1, SHA-256, SHA-384 or SHA-512 hashes of text.

Open
UUID GeneratorNew

Generate one or many random version-4 UUIDs.

Open
Timestamp ConverterNew

Convert between Unix timestamps and human-readable dates.

Open
JWT DecoderNew

Decode and inspect JSON Web Token headers and payloads.

Open
Regex TesterNew

Test regular expressions against sample text with live matches.

Open
JSON to CSV ConverterNew

Convert JSON arrays to CSV and back, right in your browser.

Open
Number Base ConverterNew

Convert numbers between binary, octal, decimal and hex.

Open
Color ConverterNew

Convert colors between HEX, RGB and HSL instantly.

Open
CSS Gradient GeneratorNew

Design CSS gradients and copy the code in one click.

Open
CSS Box Shadow GeneratorNew

Build CSS box-shadows visually and copy the code.

Open
HTML Entity Encoder & DecoderNew

Encode or decode HTML entities and special characters.

Open
Cron Expression HelperNew

Translate cron expressions into plain English.

Open
Color Contrast CheckerNew

Check color contrast against WCAG AA and AAA.

Open
  • Free with no sign-up, accounts or hidden limits
  • Most tools run privately in your browser — no uploads
  • JSON, Base64, JWT, regex, hashes, UUIDs and more
  • Instant results with nothing to install

Tooldrop's online developer tools put a full kit of everyday utilities in one place, free and with no sign-up. Format and validate JSON, convert JSON to CSV, encode and decode Base64 or URLs, decode a JWT, test a regular expression, generate hashes and UUIDs, convert number bases, and pick apart colors, CSS gradients, box-shadows, HTML entities, cron expressions and contrast ratios — all from your browser.

Most of these tools run entirely on your device, so the data you paste in is processed locally and your files and tokens are not uploaded to a server. That makes it safe to inspect a JWT with private claims, format an internal API response, or hash a secret without it ever leaving your machine. There are no usage limits, no watermarks and nothing to install — open a tool, paste your input and get a result instantly. Whether you need a quick JSON formatter mid-debug or a reliable regex tester, these free online developer tools are built to be fast, private and genuinely useful.

Frequently asked questions

Are these developer tools really free?
Yes. Every tool in this category is completely free to use with no sign-up, no account and no usage limits. There are no paywalls, watermarks or trials — open any tool and start working immediately.
Is my data uploaded when I use these tools?
For most of these tools, no. Things like the JSON formatter, Base64 encoder, JWT decoder, regex tester and hash generator run entirely in your browser using JavaScript, so your input never leaves your device and is never sent to a server. That makes them safe for sensitive data like tokens, internal payloads and secrets.
Do I need to install anything or create an account?
No. Everything runs in your web browser — there's nothing to download or install, and you never have to register. Just open a tool, paste your input and get the result.
Which developer tools are included?
The set covers JSON formatting and JSON-to-CSV conversion, Base64 and URL encoding, JWT decoding, a regex tester, hash and UUID generators, number base and color conversion, CSS gradient and box-shadow generators, HTML entity encoding, a cron expression helper and a contrast checker — with more added over time.