StartupIndies

THE LITTLE DEV HANDBOOK

Tools that fit,
with clear instructions.

From encoding to formatting, clear up everyday development questions. Pick a tool to learn what it does and when to use it.

Open the toolbox
01

Encoding & conversion

Express text, URLs, and time in the format you need.

How to use the URL encoder

Use tool

Convert text containing spaces, non-ASCII characters, or symbols to percent encoding, or decode an encoded URL parameter back to readable text. This tool encodes individual components, making it useful for query parameter names and values.

How is URL component encoding different from encoding a full URL?

This tool follows component encoding rules for query parameter names and values, so separators such as slashes and question marks are encoded too. When encoding a full URL, preserve its protocol, host, and path, and encode only the parameter values that need it.

Base64 encoding and decoding

Use tool

Base64 represents bytes as printable text and is often used for data transfer and text-safe payloads. It is an encoding format, not encryption or access control; the same input usually produces the same output.

Does Base64 encoding protect private data?

No. Base64 is reversible encoding that anyone can decode. Do not use it as encryption or to hide passwords, keys, or other sensitive data.

Online MD5 hash generator

Use tool

Calculate an MD5 digest from text for compatibility checks, non-security comparisons, and development debugging. MD5 is a one-way hash, not encryption, and should not be used for password storage or security signatures.

Can an MD5 hash be decrypted?

MD5 is a one-way hash; there is no reliable decryption that restores the original text from a digest. For password storage and other security-sensitive uses, choose a dedicated password hashing algorithm such as Argon2id, scrypt, or bcrypt.

Online Unix timestamp converter

Use tool

This timestamp tool recognizes Unix timestamps in seconds or milliseconds and displays the corresponding date and time. Unix timestamps are based on UTC; the tool shows local time and UTC side by side to help diagnose time zone differences.

How can I tell seconds from milliseconds?

A typical seconds timestamp has about 10 digits, while milliseconds have about 13. Check the unit before converting: multiplying or dividing by 1,000 incorrectly can move the result far from the intended date.

HTML entity escape and unescape

Use tool

Convert characters such as &, <, >, and quotes to HTML entities, or restore entities to text. This is useful for checking templates and content encoding. Safety still depends on the output context: HTML, attributes, JavaScript, and URLs require different handling.

Does HTML escaping completely prevent XSS?

No single escaping step can guarantee that. Escaping must match the output context; HTML text, attributes, JavaScript, and URLs each need different safety handling.

Online SHA-256 hash generator

Use tool

SHA-256 is a SHA-2 hash function that calculates a fixed-length digest for text. It is commonly used for integrity checks and debugging. It is not encryption and cannot decrypt a digest back to the original text.

How is SHA-256 different from encryption?

Hashing produces a one-way digest for integrity comparisons. Encryption uses a key and is designed to be reversible. SHA-256 alone does not keep content confidential and is not a password storage scheme.

02

Data & JSON

Make API responses and configuration easier to read.

Online JSON formatter and validator

Use tool

Paste compact or inconsistently indented JSON to apply consistent formatting and find syntax issues such as missing quotes, commas, or brackets. Formatting changes whitespace only and preserves the data structure of valid JSON.

Does formatting JSON change its data?

Formatting rearranges whitespace and line breaks only; it does not change parsed keys, values, or array order. If the syntax is invalid, the tool reports the parse error and keeps your original input.

Online JSON minifier

Use tool

JSON minification removes whitespace that does not affect parsing and produces compact, single-line text for requests or configuration. The tool checks JSON syntax before minifying.

Does minifying JSON remove fields?

No. The tool removes formatting whitespace only and keeps every object field, array item, and value.

03

Generate & validate

Create test data and inspect expressions and tokens.

Online UUID v4 generator

Use tool

UUID v4 uses random data to create a 128-bit identifier commonly used for database records, client requests, and test data. When secure random numbers are available, this generator uses the browser Web Crypto API.

Can a UUID v4 never be duplicated?

The collision probability for random UUIDs is extremely low, but not mathematically zero. It is unique enough for most applications; high-risk systems should still enforce a database uniqueness constraint.

Online JWT decoder

Use tool

Decode a JWT header and payload from Base64URL into JSON to inspect claims, issue time, and expiration. This only displays the token contents: it does not verify the signature or prove that the token is trusted.

Does decoding a JWT verify that it is authentic?

No. Decoding only reveals the visible header and payload. Signature verification requires a trusted key and explicit algorithm and validation rules. Treat tokens as sensitive data.

Online JavaScript regular expression tester

Use tool

Enter a regular expression and test text to inspect matches and capture groups. This tool uses the browser’s JavaScript RegExp syntax and is useful for frontend development and quick checks of common patterns.

Which regular expression syntax does this tool support?

It uses the current browser’s JavaScript RegExp syntax, including standard flags and capture groups. Other regex engines may differ in escaping, lookarounds, and other features.

LESS SEARCHING, MORE BUILDING

Got it? Give it a try.

Open any tool and process your input right in this browser.

Go to tools