What is Base64?

Troubleshooting

Invalid Base64: Ensure padding with "=" is correct and characters are in the Base64 alphabet (A-Z, a-z, 0-9, +, /).
Binary decode shows gibberish: The decoded data may be binary (images, executables). Save it via the download button instead of viewing as text.
Very large results: Browsers may slow down when rendering huge text. Prefer download for big outputs.
Line breaks in Base64: Some systems add line breaks every 76 characters. Our tool handles this automatically.
URL-safe Base64: Some systems use - and _ instead of + and /. You may need to replace these manually.

Security considerations

Base64 is not encryption - it's easily reversible
Don't use Base64 to hide sensitive data like passwords
Base64 increases data size by ~33%

How it works

Base64 takes groups of 3 bytes (24 bits) and converts them into 4 ASCII characters (6 bits each). If the input isn't divisible by 3, padding characters (=) are added.

Common use cases

Data URIs: Embed images directly in HTML/CSS (data:image/png;base64,iVBORw0KG...)

Email attachments: MIME encoding for binary attachments

API requests: Send binary data in JSON or XML

Configuration files: Store certificates, keys, or binary data as text

Database storage: Store binary blobs in text columns

Example

Text: Hello World!
Base64: SGVsbG8gV29ybGQh

Official documentation

Base64 — Tutorial

What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 ASCII characters. It’s commonly used to embed small files (images, fonts) into text formats, send data in URLs, or transport bytes safely through systems that are text-only.

Typical uses

Embed small images in HTML/CSS/JSON
Include binary blobs in configuration or environment variables
Safely transfer bytes through email or URL parameters

Using the Base64 tool

Text input — Paste text into “Text input”, then click Encode to get Base64. Use Decode to convert Base64 back to text.
File input — Drop a file or choose one. The tool reads it in your browser and encodes it to Base64. For large outputs you can use the Download button.
Output actions — Use Copy output to copy. The download button appears for files and large results.
History — Last 5 conversions are stored locally. Use Clear history to remove them.

Open the tool: Base64 Encoder / Decoder

Privacy & limits

All conversions run locally in your browser; no data is uploaded.
Max file size: 10 MB (to keep memory usage reasonable).

Troubleshooting

Invalid Base64: Ensure padding with “=” is correct and characters are in the Base64 alphabet.
Binary decode shows gibberish: The decoded data may be binary. Save it via the download button instead of viewing as text.
Very large results: Browsers may slow down when rendering huge text. Prefer download for big outputs.