What is Base64?

Base64 is a character encoding scheme that represents binary data using only 64 printable characters. Computers work with bytes, but not every system reliably handles raw bytes when moving information through text-only channels like email or JSON. Base64 solves that problem by turning any data—images, documents, even executable files—into a plain text string that can be safely transmitted or stored. Each group of three bytes becomes four characters, which makes the output roughly one third larger than the original, but it preserves the exact bit pattern so the data can be restored later without loss.

Common Uses

• Embedding small images directly into HTML or CSS as data URIs.
• Packaging email attachments so they survive text-only gateways.
• Serializing binary blobs in JSON or XML APIs.
• Hiding binary assets inside configuration files or source code.
• Storing cryptographic keys or hashes in databases that expect text.

How to Use This Tool

• Choose Encode to turn text or a file into Base64, or Decode to restore original data.
• Select Text mode for keyboard input or File mode to work with uploads.
• Type or drop your content and the conversion happens instantly.
• Copy the result or download it as a file for later use.

The interface reacts the moment you type or pick a file, so there is no need for extra convert buttons. Everything runs locally in your browser; nothing is sent to a server. Whether you are preparing an email attachment, verifying a hash, or embedding an icon, the tool gives quick feedback and produces clean, chunked Base64 for easy reading.

Text vs File Mode

Text mode is designed for UTF‑8 strings. It takes whatever you type or paste—regardless of language—and outputs Base64 using proper Unicode handling. File mode accepts any binary file up to five megabytes. When encoding, the file is read in memory and converted to Base64 that you can copy or save. When decoding, the tool expects the input to be a Base64 string that represents a binary file. After decoding, you can download the exact bytes with the original filename whenever possible. Because everything happens in memory, avoid huge files to keep your browser responsive.

Best Practices

• Avoid encoding very large files; the output grows quickly and may slow your browser.
• Compress data before encoding if size is a concern—Base64 does not reduce file size.
• Validate Base64 strings before decoding to prevent runtime errors.
• Strip whitespace and line breaks from Base64 when embedding in JSON or URLs.
• Keep sensitive keys offline; encode and decode locally instead of sending them over the network.

FAQs

Why does Base64 enlarge data?

Every three bytes of input are mapped to four characters, each representing six bits. That overhead adds about thirty-three percent to the original size. While larger, the tradeoff is reliability across text-based systems that might otherwise corrupt binary content.

Can I decode any Base64 string?

Only if it was created from valid binary data. Random strings may look like Base64 but fail during decoding. If you encounter errors, verify that the input contains only standard Base64 characters and padding.

Do line breaks matter?

Line breaks are often inserted every 64 or 76 characters for readability, especially in emails. This tool adds line breaks when displaying Base64 but ignores them when decoding, so you can paste data with or without spacing.

What about URL-safe Base64?

Some systems replace "+" and "/" with "-" and "_" to make strings URL friendly. You can decode those versions by swapping the characters back before processing. This tool expects standard Base64 but the concept is the same.

Is it secure to encode passwords?

Base64 is not encryption. It merely transforms data into a different representation. Anyone who obtains the string can decode it easily. For sensitive information, use proper cryptography in addition to or instead of Base64.