Free Online Base64 Encoder / Decoder
Encode text, images, and files to Base64 or decode Base64 strings — free, online, and 100% client-side. No upload required.
100% Client-Side · Your data never leaves your browserHow to Use Base64 Encoder / Decoder
Select a mode depending on your use case:
- Text mode: paste any UTF-8 text and click Encode to convert it to Base64, or paste a Base64 string and click Decode to recover the original text.
- Image mode: paste a Base64 string and see the image rendered as a preview — great for debugging CSS
data:URIs. - File mode: drag and drop any file to instantly get its Base64 representation. Works with images, PDFs, ZIPs, and any binary format.
Click the ⇄ button to swap encode/decode direction, or use Ctrl/Cmd+Enter to run and Ctrl/Cmd+K to clear.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It's commonly used to embed binary data — like images or files — inside text formats such as JSON, HTML, or email.
Is my data safe? Does it get uploaded anywhere?
No. All encoding and decoding happens entirely in your browser using JavaScript. Nothing is sent to any server. Your data never leaves your device.
What is the difference between standard Base64 and URL-safe Base64?
Standard Base64 uses + and / characters, which have special meaning in URLs. URL-safe Base64 replaces + with - and / with _, making it safe to use in URLs and filenames without percent-encoding.
Can I encode an image to Base64?
Yes! Switch to "Image" mode, paste a Base64 string to decode and preview an image, or use "File" mode to drag-and-drop any image file and get its Base64 representation.
What are common uses of Base64?
Embedding images in HTML/CSS (data URIs), encoding binary attachments in JSON APIs, storing binary blobs in databases, encoding credentials in HTTP Basic Auth headers, and handling binary data in JWT payloads.