Free Online Base64 Decoder · No Signup · Instant
Base64 Decode & Encode Online Free
Free online Base64 decoder and encoder — decode Base64 to text, encode text to Base64, convert image to Base64 and more.
No signup required. 100% private & secure. Works in your browser.
100% private & secure
Runs in your browser
No watermark
Text Input
No file chosen
Base64 Output
100% Private
All encoding and decoding runs in your browser. Data never leaves your device.
Instant Results
Convert text or files to Base64 and back in milliseconds.
Files Supported
Encode images, PDFs, documents — any file type to Base64.
What is Base64 used for? — Online Base64 Decoder & Encoder
Embed images in HTML/CSS
Convert images to Base64 and embed them directly in your code — no separate image file needed.
API authentication tokens
Encode credentials for HTTP Basic Auth and Bearer token headers in REST APIs.
Email attachments
Email protocols use Base64 to encode binary attachments for safe text-based transmission.
JSON & data transfer
Safely include binary data inside JSON payloads and text-based data transfer formats.
Frequently Asked Questions
Base64 is a method of encoding binary data as ASCII text. It converts any data — text, images, files — into a string of characters that can be safely transmitted through text-based systems like email, APIs, HTML and JSON.
Select Decode mode, paste your Base64 string into the input box, and click Decode. The original text appears instantly. No signup, no watermark, completely free. If the Base64 contains an image, a preview is shown automatically.
Yes — 100% private and secure. All encoding and decoding runs entirely in your browser using JavaScript. Your data never leaves your device and is never sent to any server.
Yes. Click "Upload file", select any file — image, PDF, document — and the tool converts it to a Base64 string instantly. This is useful for embedding images in HTML or CSS, or encoding files for API transmission.
Yes. If your Base64 string contains an image, Zappy automatically detects it and shows a live preview below the output. You can also download the decoded file directly.
Encoding converts text or binary data into a Base64 string — making it safe for transmission. Decoding reverses the process — converting a Base64 string back into the original text or file. Use Encode when sending data, Decode when receiving it.