Five small developer tools that save more time than you'd expect.

1. URL encoding: the ampersand that breaks everything

Picture a query parameter whose value is 'tea & coffee'. Dropping that text straight into a URL can make the ampersand look like the start of another parameter. encodeURIComponent turns the value into a component-safe representation. Reverse the process with a decoder when you need to inspect a log.

The distinction matters: encode a parameter value, not the full URL if you want its colons, slashes and query separators to stay meaningful. RezSat's URL Encoder & Decoder exposes the two operations side by side.

2. Base64: transport format, not secrecy

Base64 makes arbitrary bytes look like familiar ASCII characters. It is useful in places that require text, but anybody can decode it. Never treat Base64 as encryption or use it as a substitute for password handling.

UTF-8 trips people up. A quick converter should be able to round-trip Sinhala, accented characters and emoji, not merely English letters. RezSat's Base64 Text Converter deliberately handles UTF-8 and warns if the decoded bytes aren't valid text.

3. Unix timestamps: seconds versus milliseconds

The same timestamp can appear as ten digits in seconds or thirteen digits in milliseconds. Read the number in the wrong unit and you get a spectacularly wrong date. Converting to an explicit UTC ISO 8601 string makes bugs easier to talk about and test.

Use the Unix Timestamp Converter when a database column, JWT claim, API response or event log needs a human-readable date. Always check whether your source is seconds or milliseconds before you draw conclusions.

4. JSON formatting: make the structure visible

Compact JSON is great for machines and awful for eyeballing. Pretty-print it when you need to spot a nested field or a missing closing bracket; minify it before copying into a place with space constraints. The RezSat JSON Formatter validates the input and reports parsing errors.

One warning that saves time: JavaScript object literals are not always JSON. JSON keys need double quotes, comments aren't allowed, and trailing commas are invalid.

5. Password generation: take randomness seriously

When you need a fresh test credential, don't type 'Test1234!' or recycle a production password. Use a password generator backed by the browser's cryptographic random-number generator and make the result unique. RezSat's Password Generator lets you choose length and character classes and creates passwords locally.

For real accounts, use a password manager and multi-factor authentication where available. A generated password is only helpful if you can store it safely.

And when you're testing regex…

Use regex101 instead of guessing what a long pattern means. The explanations, test strings and engine selection turn an opaque expression into something you can reason about. Treat code generated by any online helper as a starting point and keep your real tests.