Why does Base64 add padding with = characters?

Base64 encodes data in 3-byte chunks (24 bits), producing 4 characters per chunk. When the input length is not divisible by 3, padding with "=" fills the remaining space. One "=" means 2 bytes in the final chunk; two "==" means 1 byte. Padding ensures decoders know where the data ends. Example: "Hi" encodes to "SGk=" (one padding character).

Is Base64 encoding secure?

No. Base64 is an encoding method, NOT encryption. It obfuscates data but provides zero security. Anyone can decode Base64 instantly. Never use Base64 for sensitive data like passwords or API keys unless combined with proper encryption (AES, RSA). Base64 is for data transport and representation, not confidentiality.

Can I Base64 encode images or files?

Yes. Base64 can encode any binary data, including images (JPG, PNG), PDFs, or ZIP files. This is useful for embedding images in HTML/CSS (data URIs: data:image/png;base64,...), sending files via JSON APIs, or storing binary data in databases. However, Base64 increases file size by 33%, so use it only when necessary.

What is the difference between Base64 and URL-safe Base64?

Standard Base64 uses "+", "/", and "=" characters that cause issues in URLs and filenames. URL-safe Base64 (RFC 4648) replaces "+" with "-" and "/" with "_", and optionally removes padding "=". This variant is used in JWTs, URL parameters, and file naming. Both decode to the same binary data; only character sets differ.

Why use Base64 when it increases file size?

Base64 is used when binary data must be transmitted through text-only channels: email (MIME attachments), JSON APIs (no binary support), XML documents, HTML data URIs, or database TEXT columns. Despite the 33% size increase, it guarantees safe transport without data corruption. For modern APIs with multipart/form-data support, send binary data directly instead of Base64.

Base64 Encoder/Decoder - Free Online Tool

How to Encode/Decode Base64

Paste text or Base64 string into the input field
Select Encode or Decode mode
Click the convert button to process
Copy the encoded or decoded result

Base64 Encoder Features

Bidirectional Conversion: Encode text to Base64 and decode Base64 to text
Input Validation: Detects invalid Base64 strings when decoding
Error Detection: Helpful messages for malformed input
Handles Special Characters: Correctly encodes Unicode and symbols
Real-Time Processing: Instant results as you type
100% Free: No limits on text length or usage

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data as ASCII characters. It converts groups of 3 bytes into 4 printable characters (A-Z, a-z, 0-9, +, /), making binary data safe for text-based protocols.

Common use cases: Embedding images in HTML/CSS as data URLs (data:image/png;base64,...), sending binary attachments in email (MIME), encoding API tokens and credentials, transmitting binary files through JSON APIs, and storing binary data in text-based formats like JSON or XML.

Important: Base64 is NOT encryption. It's encoding for transport, not security. Anyone can decode Base64 strings. Never use Base64 alone for sensitive data—use proper encryption (AES, RSA) instead. Base64 increases data size by about 33% (3 bytes become 4 characters).

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Base64 Encoder & Decoder

How to Encode/Decode Base64

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What is Base64 Encoding?

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