Encode and decode Base64 text instantly online. Convert text to Base64 or decode Base64 strings back to readable text. Free, no signup needed.
What Is Base64 Encoder & Decoder Online?
Base64 is an encoding scheme that converts binary data into a string of ASCII characters. It uses 64 characters — A–Z, a–z, 0–9, plus (+) and slash (/) — to represent data safely in environments that only support text, such as email bodies, URLs and HTML attributes.
Base64 encoding increases the data size by roughly 33%, so it is not a compression method. Its purpose is safe transport. When you embed an image in a CSS file, send a binary attachment through an email protocol or include binary tokens in a URL, Base64 ensures the data survives without corruption.
How to Use This Tool
Choose whether you want to encode (text to Base64) or decode (Base64 to text).
Paste your input into the text area.
For file encoding, use the file upload button to select a file from your device.
Click "Convert" to see the result instantly.
Copy the output using the copy button.
Tips & Best Practices
Base64 is encoding, not encryption — it provides no security and is trivially reversible.
For embedding images in HTML or CSS, prepend the appropriate data URI prefix (e.g. data:image/png;base64,).
Large files will produce very long Base64 strings — consider whether direct file serving is more appropriate.
UTF-8 text with special characters (emoji, accented letters) will encode correctly but produce longer output.
Common Use Cases
Embedding small images directly in HTML or CSS data URIs to reduce HTTP requests.
Encoding authentication tokens for inclusion in HTTP headers.
Converting binary data for storage in JSON or XML where binary is not supported.
Decoding Base64 strings found in API responses, emails or log files.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a method of converting binary data into ASCII text. It is commonly used to embed images in HTML/CSS, send data in URLs, and encode email attachments.
How do I decode Base64 text?
Paste your Base64 string into the input, select Decode mode and click Convert. The decoded text appears instantly.
Is there a size limit?
Free users can encode or decode text of any length. Premium users can also upload files for Base64 conversion.