What is Base64 encoding used for?

Base64 is used to encode binary data into ASCII text for safe transmission through text-based protocols. Common uses include embedding images in CSS/HTML (data URIs), encoding email attachments (MIME), encoding API authentication tokens (HTTP Basic Auth), and transmitting binary data in JSON.

What's the difference between standard and URL-safe Base64?

Standard Base64 uses + and / characters, which have special meaning in URLs. URL-safe Base64 replaces these with - and _ to allow safe inclusion in URL query parameters and path segments without percent-encoding.

Does Base64 encrypt my data?

No. Base64 is an encoding, not encryption. Anyone can decode a Base64 string back to the original data. Never use Base64 as a security measure — use proper encryption for sensitive data.

Is there a size limit?

No fixed limit. The tool can encode text and files limited only by your browser's available memory. However, note that Base64 encoding increases data size by approximately 33%.

Base64 Encoder — Encode Text to Base64

What Is Base64 Encoding?

Base64 Encoding is a binary-to-text encoding scheme that represents binary data in an ASCII string format. By translating 8-bit binary data into 6-bit printable characters, Base64 ensures data is safely transmitted across network protocols (such as HTTP, MIME email, and JSON payloads) without corruption from character set conversions or strip-down proxies.

Key Features of OneToolBox Base64 Encoder

UTF-8 Unicode & International Script Support: Correctly handles non-ASCII text, emojis, Chinese, Arabic, Cyrillic, and special symbols using native JavaScript TextEncoder.
URL-Safe Encoding: Automatically substitutes + with -, / with _, and strips trailing = padding characters for safe inclusion in HTTP GET query parameters and REST URLs.
MIME RFC 2045 Line Chunking: Formats output into max 76-character lines, matching official email header and MIME specification standards.
Line-by-Line Encoding: Processes multi-line documents independently line by line for bulk text list conversions.
100% In-Browser Privacy: Zero server calls or external API network transmissions. All conversions take place in your browser client-side.

Base64 vs URL-Safe Base64 Comparison

Feature	Standard Base64	URL-Safe Base64
Character set	`A-Z, a-z, 0-9, +, /`	`A-Z, a-z, 0-9, -, _`
Padding character	Uses trailing `=`	Paddings omitted
Primary Use Cases	MIME Email, Data URLs, Cryptography	URL Query Parameters, Web Tokens (JWT), API Keys

Frequently Asked Questions

Standard Base64 uses + and / characters which carry special meanings in URLs and GET parameters. URL-safe Base64 replaces + with - and / with _, omitting trailing padding '=' characters so the output can be safely used in web addresses.

MIME specifications (RFC 2045) require Base64 encoded output to be split into lines of at most 76 characters separated by line breaks. This ensures compatibility with legacy email systems and data streams.

Base64 Encoder

What Is Base64 Encoding?

Key Features of OneToolBox Base64 Encoder

Base64 vs URL-Safe Base64 Comparison

Frequently Asked Questions

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Frequently Asked Questions

What is Base64 encoding used for?

What's the difference between standard and URL-safe Base64?

Does Base64 encrypt my data?

Is there a size limit?