🔑 Encode / Decode Tools

Encode and decode data with Base64, JWT, URL encoding, HTML entities, and Unicode converters. Choose a tool below to get started.

Base64 Encode/Decode Encode and decode Base64 strings instantly. Supports text and binary data encoding with UTF-8. Essential developer tool. JWT Decoder Decode JSON Web Tokens (JWT) instantly. View header, payload, claims, and expiration time. No server-side processing. URL Encoder/Decoder Encode and decode URL components. Convert special characters to percent-encoding for safe URL usage. Developer-focused tool. HTML Entity Encoder Convert characters to HTML entities and decode entities back to characters. Supports named and numeric HTML entities. Unicode Code Point Converter Convert characters to Unicode code points (U+XXXX) and back. View hex, decimal, and UTF-8 byte representations.

About Encoding and Decoding Tools

Encoding converts data from one format to another for safe transmission or storage. Decoding reverses the process. As a developer, you encounter encoding constantly: API payloads arrive as Base64, URLs must percent-encode special characters, HTML must escape angle brackets to prevent injection, and JWTs carry encoded claims in every authenticated request. These tools let you inspect and transform encoded data directly in your browser — no server, no libraries, no setup.

Base64 Encoding

Base64 represents binary data using only 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It is not encryption — anyone can decode it — but it solves the problem of transmitting binary data over channels that only support text, such as email (MIME) or JSON fields. Common uses include embedding images in CSS as data URIs, encoding binary file content in API responses, and storing binary credentials in environment variables. Base64 increases data size by approximately 33%.

JWT Decoding

A JSON Web Token (JWT) consists of three Base64URL-encoded parts separated by dots: a header (algorithm and token type), a payload (claims such as user ID and expiration time), and a signature. The JWT Decoder splits these sections and displays the decoded JSON so you can inspect claims, check expiration times, and debug authentication issues without needing to write any code. Note: the decoder only reads the token — it does not verify the signature, which requires the secret key.

URL Encoding

URLs can only contain a limited set of characters. Special characters like spaces, ampersands, and equals signs must be percent-encoded (e.g., space becomes %20, & becomes %26) so browsers and servers interpret them correctly. The URL Encoder/Decoder is essential when building query strings, debugging HTTP requests, or constructing redirect URLs that contain parameters.

HTML Entities

HTML reserves certain characters for its own syntax: < and > define tags, & starts entity references, and " delimits attribute values. When these characters appear in text content, they must be escaped as HTML entities (&lt;, &gt;, &amp;, &quot;) to prevent the browser from misinterpreting them as markup. This is also a critical security practice — failing to escape user input before inserting it into HTML is the root cause of XSS (Cross-Site Scripting) vulnerabilities.

Frequently Asked Questions

Is Base64 the same as encryption?

No. Base64 is encoding, not encryption. It is completely reversible without a key and provides no confidentiality. Never use Base64 to "hide" sensitive data — use proper encryption (AES-256) or hashing (bcrypt, Argon2) instead.

How do I decode a JWT without a library?

Split the token at each dot to get three parts. Base64URL-decode the first two parts (header and payload) to get JSON. The third part (signature) is a cryptographic hash that requires the secret key to verify. Our JWT Decoder handles the decoding automatically.

What is the difference between URL encoding and HTML encoding?

URL encoding (percent-encoding) converts characters for safe use in URLs. HTML encoding converts characters to HTML entities for safe display in HTML documents. A space becomes %20 in a URL and &nbsp; or just a space in HTML. They serve different purposes and should not be used interchangeably.