Base64 Encoder/Decoder
Data is processed securely within your browser and not sent to any server.
What is a Base64 Encoder/Decoder?
A Base64 Encoder/Decoder is a tool that converts text into a Base64 string (encoding) or restores a Base64 string back to its original text (decoding). It's widely used in API communication, email attachment handling, authentication token debugging, and more. It also supports line break (76-character MIME format) and URL-safe Base64 conversion. ToolVill's Base64 tool runs 100% in your browser, so your data is never sent to an external server.
Key Features
- Real-Time Conversion: Encoding/decoding results appear instantly as you type — no button click needed.
- Unicode Support: Accurately encode/decode multilingual text including Korean, Japanese, and emoji.
- Line Break (76 chars): Automatically insert line breaks every 76 characters for MIME (email) or PEM certificate compliance.
- URL-safe Base64: Convert + to -, / to _, and remove padding (=) for safe use in JWT tokens and URL parameters.
- Swap Input/Output: Swap the result into the input field with one click for instant reverse conversion.
- Fully Local Processing: All data is processed only within your browser's memory and never transmitted to any external server.
When Should You Use It?
- When decoding Base64 strings found in API responses or JWT tokens to inspect their content
- When converting images or files to Data URIs for embedding directly in code
- When you need MIME-compliant line breaks (76 characters) for email or PEM certificate formats
- When you need URL-safe Base64 (+ → -, / → _) for JWT tokens or web API parameters
- When transmitting email attachments or binary data as text
Frequently Asked Questions (FAQ)
What is Base64 encoding?
Base64 encoding is a method of converting binary data into an ASCII string. It's commonly used for email attachments, URL parameters, and API communication where binary data needs to be transmitted as text.
When should I use the line break (76 chars) option?
The MIME email standard and PEM certificate format require Base64 strings to be wrapped at 76 characters per line. Enable this option to automatically insert line breaks at the correct intervals.
What is URL-safe Base64?
Standard Base64 uses + and / characters, which have special meanings in URLs and can cause issues. URL-safe mode replaces + with -, / with _, and removes padding (=) to produce Base64 strings that are safe for JWT tokens and URL parameters.
Does it support Korean and other Unicode characters?
Yes. ToolVill's Base64 tool operates on UTF-8 Unicode, so it accurately handles Korean, Japanese, emoji, and all other Unicode characters.
Is Base64 the same as encryption?
No. Base64 is an encoding scheme, not encryption. Anyone can decode it, so never use it to protect sensitive data.
Is my data sent to a server?
No. All encoding/decoding is performed entirely within your browser.