Input Text
Base64 Output
Base64 Encoder/Decoder
Encode text and files to Base64 or decode Base64 strings instantly
What This Tool Does
This Base64 encoder converts text and binary files into Base64 format, a text representation of binary data. The decoder reverses the process, turning Base64 strings back into readable text or downloadable files.
All encoding and decoding happens in your browser. When you paste text or upload a file, it processes the data locally without sending anything to a server.
Who Needs This
Web developers embedding images in CSS or HTML use Base64 encoding to include small images directly in code. This reduces HTTP requests and can improve page load times for icons and small graphics.
Software engineers working with APIs that require binary data in JSON payloads use Base64 encoding. Since JSON is text-based, binary files like images or PDFs must be encoded before transmission.
Email systems use Base64 to encode attachments. If you've ever looked at the raw source of an email with attachments, the encoded sections are Base64-encoded files.
Key Features
Text Encoding
Convert any text string to Base64 format. Useful for encoding credentials, tokens, or any text that needs binary-safe representation.
File Encoding
Upload files of any type and convert them to Base64 strings. Works with images, documents, and binary files up to 10MB.
Base64 Decoding
Paste a Base64 string and decode it back to readable text. Validates the input and shows errors for malformed Base64.
Two-Way Conversion
Switch between encode and decode modes with a single click. The interface adapts to show relevant options for each mode.
Copy and Download
Copy encoded or decoded output to clipboard for pasting elsewhere, or download the result as a text file.
Client-Side Processing
All operations run in your browser. Files and text stay on your device throughout the encoding and decoding process.
When to Use Base64 Encoding
Base64 encoding is useful in specific scenarios where binary data needs to be represented as text:
Data URLs in HTML/CSS: Embed small images directly in web pages using data:image/png;base64,... URLs. This works well for icons and small graphics but increases HTML file size.
JSON API Payloads: When APIs need to transmit binary files in JSON format, Base64 encoding allows the binary data to be represented as a string field.
Basic Authentication: HTTP Basic Authentication encodes username:password combinations in Base64. Note that Base64 is encoding, not encryption, so always use HTTPS.
Email Attachments: Email protocols like SMTP use Base64 to encode binary attachments for transmission over text-based protocols.
Important Limitations
Base64 is not encryption. It's an encoding scheme that makes binary data text-safe, but anyone can decode it. Never use Base64 as a security measure for sensitive data.
Base64 encoding increases data size by approximately 33%. A 100KB file becomes roughly 133KB when encoded. This matters for large files or bandwidth-constrained applications.
For large files, Base64 encoding in the browser may slow down or freeze the page temporarily. The tool handles files up to 10MB, but performance depends on your device's processing power.
Privacy and Security
This tool processes all data in your web browser using JavaScript. When you enter text or upload a file, nothing is transmitted to any server. The file or text is read and processed locally on your device.
This matters when encoding sensitive information like API keys, authentication tokens, or private files. Since processing is client-side, there's no risk of exposing data through network transmission.
The tool doesn't save your input to browser storage or cache. When you close the tab, all data is cleared from memory.
Common Questions
No. Base64 is encoding, not encryption. It converts binary data to text format but provides no security. Anyone can decode Base64 strings instantly. Never rely on Base64 for protecting sensitive information.
Base64 encodes every 3 bytes of binary data as 4 text characters. This 3:4 ratio means the output is approximately 33% larger than the input. The overhead is necessary to represent binary data using only text-safe characters.
No. All encoding and decoding happens in your browser. Files are read locally on your device and never sent anywhere.
Yes. Base64 encoding works with any file type including images, PDFs, documents, and binary files. The tool accepts files up to 10MB in size.
This error appears when trying to decode text that isn't valid Base64. Base64 strings only contain letters A-Z, a-z, numbers 0-9, plus (+), slash (/), and equals (=) for padding. Any other characters or incorrect formatting causes this error.
Use Base64 when you need to embed binary data in text-based formats like JSON, XML, or HTML. It's practical for small images in CSS, API payloads containing files, or email attachments. Avoid it for large files where the 33% size increase matters.