Base64 Encoder & Decoder Online – Convert Data Instantly

Encode Files or Decode Base64 Strings for Developers

How It Works

Paste your input

Type or paste any text, JSON, or binary data string into the input field. For files, use the upload option.

Choose encode or decode

Click Encode to convert raw data to a Base64 string, or Decode to reverse a Base64 string back to readable text.

Copy the output

The result appears instantly. Copy it with one click to use in your HTML, CSS, API calls, or code.

Embed or transmit

Paste encoded strings directly into src attributes, Authorization headers, or JSON payloads without escaping issues.

Common Base64 Use Cases

Base64 appears throughout web development wherever binary data needs to travel through text-only channels.

Use Case	What Gets Encoded	Why
Inline images in HTML/CSS	PNG, SVG, GIF	Avoids extra HTTP request for small icons
JWT tokens	JSON header + payload	Compact, URL-safe transmission
Email attachments (MIME)	Binary files	RFC 2045 email encoding standard
API authentication	username:password	HTTP Basic Auth header format
Data URLs	Images, fonts	Embed resources directly in code
Webhook payloads	Binary event data	Text-safe delivery over HTTP

Understanding Base64 Encoding

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters: A–Z, a–z, 0–9, and the symbols + and /. Every 3 bytes of input become 4 characters of Base64 output — which is why encoded data is always about 33% larger than the original.

Base64 is not encryption. Anyone can decode a Base64 string instantly — it provides no security. Its sole purpose is encoding: converting binary data into a format that can pass through systems designed to handle text, such as email, JSON APIs, or HTML attributes.

The URL-safe variant replaces + with - and / with _ to avoid conflicts with URL special characters — this variant is used in JWTs and web-safe data URLs.

FAQ

Why is Base64 encoding used in web development?

It converts binary files (images, fonts, attachments) into text that can be embedded directly into HTML, CSS, and JSON. It's widely used for data transmission, API communication, and creating data URLs.

Is Base64 secure for sensitive data?

No — Base64 is not encryption. It should only be used for safe, non-confidential assets. Sensitive data must use proper cryptography instead.

What types of data can be converted using Base64 encoding?

Base64 can encode text, JSON, HTML, images, PDFs, fonts, audio, and binary data, making it useful for embedding resources inside web pages, CSS files, or API payloads.