Smartweb.tools Free browser-based developer tools including Base64 encoder/decoder, URL encoder, JSON formatter, Unix timestamp converter, CSS and HTML minifier. No registration.

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Developer Tools — free online tools

Browser-based utilities for web developers and programmers

Developers spend a significant amount of time on small encoding, formatting and conversion tasks. Switching between terminals, browser consoles and online tools interrupts the flow of work. Our developer tools collection puts the most commonly needed utilities in one place, accessible from any browser without login or installation.

Base64 Encoder and Decoder

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters. It is widely used in email attachments (MIME), embedding images in CSS and HTML via data URLs, storing binary data in JSON, and encoding credentials in HTTP Basic Authentication headers. The encoder converts plain text or binary data to Base64, and the decoder reverses the process — handling Unicode characters correctly, which many simpler implementations fail to do.

URL Encoder and Decoder

URLs can only contain a limited set of characters. Spaces, special symbols and non-ASCII characters must be percent-encoded before they can appear in a URL. For example, a space becomes %20 and an ampersand becomes %26. Use the URL encoder to prepare query parameters for API requests, and the decoder to read encoded URLs returned by servers, browsers or analytics tools.

JSON Formatter and Validator

Raw JSON from APIs and log files is often delivered as a single unbroken line. The JSON formatter parses the input, validates that it is correct JSON, and re-formats it with consistent indentation for easy reading. Invalid JSON triggers an error message that identifies the location of the syntax problem, helping you debug API responses and configuration files quickly.

Unix Timestamp Converter

Unix timestamps are integers that count the number of seconds elapsed since 1 January 1970 UTC. They are used by databases, APIs, log files and virtually every programming language for storing and comparing dates without timezone ambiguity. The converter translates any Unix timestamp to a human-readable date in ISO, UTC and local formats, and converts any selected date and time back to a Unix timestamp in both seconds and milliseconds.

CSS and HTML Minifier

Minification removes unnecessary whitespace, comments and formatting from CSS and HTML files, reducing their size and improving page load speed. The CSS minifier collapses whitespace around selectors and properties, removes block comments and trims redundant semicolons. The HTML minifier collapses whitespace between tags and removes HTML comments. Both tools show the original size, the minified size and the percentage reduction so you can evaluate the benefit immediately.

  • Base64 Encoder Decoder — Encode text or data to Base64 format and decode Base64 strings back to plain text instantly in your browser.
  • URL Encoder Decoder — Encode special characters in URLs using percent-encoding and decode percent-encoded URLs back to readable text.
  • Color Converter — Convert colors between HEX, RGB and HSL formats instantly with a live color preview and one-click copy for each format.
  • Unix Timestamp Converter — Convert Unix timestamps to human-readable dates and times, and convert any date back to a Unix timestamp in seconds or milliseconds.
  • CSS Minifier — Minify CSS code by removing comments and unnecessary whitespace to reduce file size and improve website loading speed.
  • HTML Minifier — Minify HTML code by removing comments and collapsing whitespace to reduce page size and improve website performance.
  • Binary Decimal Hex Converter — Convert numbers between decimal, binary, hexadecimal and octal number systems instantly with one-click copy for each format.