How to Use the Base64 Encoder & Decoder
- Choose your mode — Click "Encode" to convert text to Base64, or "Decode" to convert Base64 back to readable text.
- Enter your data — Type or paste your text (or Base64 string) into the input area. The conversion happens instantly as you type.
- Copy the result — Click "Copy" to copy the output to your clipboard. Use "Swap" to move the output back to input for round-trip testing.
What Is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters: A-Z, a-z, 0-9, +, and / (with = for padding). It was designed to safely transmit binary data through systems that only support text.
Common Uses for Base64
- Data URIs — Embedding images directly in HTML or CSS using
data:image/png;base64,... instead of separate image files.
- Email attachments — MIME encoding uses Base64 to attach files to emails.
- API payloads — Embedding binary data (images, files, certificates) in JSON or XML payloads that only support text.
- Authentication headers — HTTP Basic Authentication encodes
username:password as Base64 in the Authorization header.
- Storing binary in databases — When a text-only column needs to store binary data.
Base64 Is Not Encryption
A common misconception: Base64 does not provide any security. It's an encoding format, not encryption. Anyone can decode a Base64 string instantly. Never use Base64 to "hide" passwords, API keys, or sensitive data — it provides zero protection.
Why Does Base64 Increase Size?
Base64 encoding increases data size by approximately 33%. Every 3 bytes of input become 4 characters of output. A 1 MB file becomes approximately 1.33 MB when Base64 encoded. This overhead is the trade-off for ensuring the data is safe to transmit through text-only channels.
UTF-8 Support
This tool properly handles UTF-8 characters, including emojis, accented characters (like é and ü), CJK characters, and other multi-byte Unicode text. Many Base64 tools fail on non-ASCII input — this one encodes and decodes them correctly.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a way to represent binary data using only printable ASCII characters (A-Z, a-z, 0-9, +, /). It's commonly used to embed images in HTML/CSS, transmit data in APIs and emails, and store binary data in text-based formats like JSON and XML.
Is this Base64 tool free?
Yes, completely free. No sign-up, no hidden fees. Encode and decode as much data as you need.
Is my data uploaded to a server?
No. All encoding and decoding happens locally in your browser using JavaScript. Your data never leaves your device — we never see, store, or have access to your content. This is especially important for Base64, since developers often encode API keys or credentials.
Does Base64 encrypt my data?
No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string back to its original form. Do not use Base64 to protect sensitive information — it provides zero security.
Why does Base64 make data larger?
Base64 encoding increases data size by approximately 33%. Every 3 bytes of input become 4 ASCII characters of output. This overhead is the trade-off for ensuring the data is safe to transmit through text-only systems.
Does this tool support UTF-8 and emojis?
Yes. This tool properly handles UTF-8 characters including emojis, accented characters, Chinese/Japanese/Korean text, and other non-ASCII characters. Many Base64 tools fail on multi-byte characters — this one handles them correctly.