Text to Base64 Encoder
Base64 to Text Decoder
Base64 Encode & Decode Online — Free Converter Tool
Convert text, files, and binary data to Base64 encoding instantly. Encode or decode with full UTF-8 support, URL-safe mode, and one-click copy — all processed locally in your browser.
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that converts binary data into a string of 64 printable ASCII characters: uppercase letters (A-Z), lowercase letters (a-z), digits (0-9), plus (+), and forward slash (/). It works by taking every three bytes of input and splitting them into four 6-bit groups, each mapped to one of the 64 characters. When the input length is not a multiple of three, the output is padded with one or two equals signs (=).
Defined in RFC 4648, Base64 is widely used for safely transporting binary data through text-only channels such as email (MIME), JSON payloads, HTML data URIs, and URL query parameters. It is important to note that Base64 is not encryption — it provides no security or confidentiality. It is purely a data encoding format designed for reliable transport across systems that only support text.
Features of Our Base64 Tool
Encode & Decode Text
Convert plain text to Base64 and back. Paste any string and get the encoded output instantly, or decode a Base64 string to reveal its original content.
Real-Time Conversion
See results as you type with live encoding and decoding. The output updates automatically with every keystroke for a frictionless workflow.
URL-Safe Base64
Toggle URL-safe mode to replace + with - and / with _, making the output safe for URLs, filenames, and JWT tokens without additional percent-encoding.
File Encoding
Upload images, documents, or any binary file and convert them to Base64 strings. Perfect for generating data URIs or embedding assets directly into HTML, CSS, or JSON.
UTF-8 Support
Full support for multi-byte UTF-8 characters including emojis, accented letters, CJK scripts, and symbols. International text encodes and decodes correctly every time.
Copy & Download
Copy encoded or decoded results to your clipboard with one click, or download as a file. Share results quickly or save them for later use in your projects.
How to Encode and Decode Base64
Paste Text or Upload a File
Type or paste the text you want to convert into the input area, or upload a file to encode its contents as Base64.
Choose Encode or Decode Mode
Select whether to encode plain text into Base64 or decode an existing Base64 string. Switch between standard and URL-safe variants as needed.
Copy the Result or Download
Your converted output appears instantly. Copy it to your clipboard with a single click or download it as a file.
Standard vs URL-Safe Base64
Standard Base64
Uses + and / alongside the alphanumeric set, with = padding to make the output length a multiple of four.
Best for: Email attachments (MIME encoding), data URIs in HTML and CSS, and contexts where the full Base64 alphabet is accepted.
URL-Safe Base64
Replaces + with - and / with _, and often omits = padding. This avoids conflicts with URL-reserved characters.
Best for: URL query parameters, filenames, JWT tokens, and situations where the string must be URI-safe without percent-encoding.
Common Use Cases for Base64
- Email Attachments (MIME): Embed binary attachments like images and PDFs inside plain-text email messages.
- Data URIs in HTML/CSS: Inline small images, fonts, or SVGs directly in markup to reduce HTTP requests.
- API Payloads & JSON Data: Encode binary content within JSON payloads for safe transport through text-based protocols.
- JWT Tokens: JSON Web Tokens use URL-safe Base64 to encode header and payload segments for stateless auth.
- Embedding Images in Code: Store small icons or logos as Base64 strings in source code or config files.
Frequently Asked Questions
What is Base64 used for?
Base64 encodes binary data into ASCII text for safe transmission through text-only channels. Common uses include email attachments, data URIs, API payloads, JWT tokens, and storing binary data in JSON or XML.
Is Base64 encryption?
No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string without a key. It provides zero security. For protecting sensitive data, use a proper encryption algorithm such as AES.
Why is Base64 output larger than input?
Base64 encodes every 3 bytes into 4 ASCII characters, resulting in roughly a 33% size increase. This overhead is the trade-off for representing binary data using only printable characters.
What is URL-safe Base64?
A variant replacing + with - and / with _ so the output works directly in URLs and filenames without percent-encoding. Defined in RFC 4648, it is commonly used in JWT tokens and web APIs.
Can Base64 handle binary files?
Yes. Base64 can encode any binary file — images, PDFs, audio, or archives. The output is a plain ASCII string that can be stored in text fields, embedded in HTML, or sent through text protocols.
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Pair Base64 encoding with our other developer utilities for a complete data transformation workflow. Every tool runs locally in your browser for maximum privacy and speed.