Base64 Encoder & Decoder
Encode text or files as Base64, or decode Base64 strings to their original form. Create data URIs and inspect text or binary output.
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Start Encoding and Decoding
Choose encode or decode, then enter text or select a file
Base64 Encoder & Decoder
Encode text or files as Base64, or decode Base64 strings to their original form. Use the result for data URIs, API development, or content inspection. Processing runs locally in your browser.
Input
💡 About Base64
Base64 encoding converts binary data into ASCII text format:
- Uses characters: A-Z, a-z, 0-9, +, /
- Increases data size by ~33%
- Safe for URLs, emails, and web transmission
- Commonly used in data URIs and APIs
- 100% client-side processing for security
Ready to Process
Enter text or upload a file to encode to Base64
How to Use Base64 Encoder & Decoder
- 1
Choose Your Mode
Select 'Encode' to convert text or files into Base64 format, or 'Decode' to convert Base64 strings back to their original form.
Tip:Use encoding for data URIs and API payloads; use decoding to inspect existing Base64 content. - 2
Input Your Data
For encoding, choose between text input or file upload. For decoding, paste your Base64 string into the text area. Files up to 100MB are supported.
Tip:Use the 'Load Example' button to see how Base64 encoding works with sample data. - 3
Process and Copy Results
Click the encode/decode button to process your input. The result will show size information and can be copied to your clipboard with one click.
Tip:Base64 encoding increases data size by about 33% - this is normal and expected for the format.
Security & Privacy
- All encoding/decoding is performed in your browser.
- Text and files are never uploaded, logged, or stored.
- For large files, prefer chunking to avoid memory spikes.
Features & Benefits
Bidirectional Conversion
Encode text and files to Base64 format or decode Base64 strings back to their original form with automatic detection.
Large File Support
Process files up to 100MB with optimized performance for handling large documents, images, and binary data efficiently.
Data URI Generation
Create data URIs for web development by encoding images and files for direct embedding in CSS, HTML, and JavaScript.
Binary Data Inspector
Displays decoded binary data as a hex dump for file-structure inspection and debugging.
Size Analytics
Real-time size comparison showing original vs encoded data size with compression ratios and file statistics.
Privacy-First Processing
100% client-side processing ensures your sensitive data never leaves your browser - no uploads or server storage.
Frequently Asked Questions
Is my data secure and private?
Absolutely! All Base64 encoding and decoding happens entirely in your browser using JavaScript. No data is ever sent to our servers or stored anywhere.
Why does Base64 encoding make files larger?
Base64 encoding converts binary data to ASCII text using only 64 characters (A-Z, a-z, 0-9, +, /). This encoding method increases the data size by approximately 33% but makes the data safe for text-based transmission.
What file types can I encode?
You can encode any file type to Base64 - images, documents, executables, etc. Files up to 100MB are supported for optimal performance.
Can I decode any Base64 string?
Yes, as long as it's valid Base64 format. The tool will attempt to decode as UTF-8 text first, but if that fails (for binary data), it will show a hex dump of the decoded bytes.
What are common uses for Base64 encoding?
Base64 is commonly used for: data URIs in web development, email attachments, API data transmission, embedding images in CSS/HTML, HTTP Basic Authentication, and storing binary data in text-based formats like JSON or XML.
How do I create a data URI from an image?
Upload your image file in encode mode. The result will be a Base64 string. To create a data URI, prefix it with 'data:[mime-type];base64,' - for example: 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA...'
Technical Specifications
Use Cases & Applications
Data URI Creation
Encode small images or icons to create data URIs that can be embedded directly in CSS or HTML, eliminating the need for separate image files.
API Data Encoding
Encode binary data or special characters for safe transmission through APIs, especially when dealing with JSON payloads that don't handle binary data well.
Email Attachment Processing
Decode Base64-encoded email attachments to understand their content, or encode files for programmatic email sending through APIs.
Configuration File Encoding
Encode sensitive configuration data or certificates into Base64 format for secure storage in environment variables or configuration files.
Basic Authentication Headers
Decode HTTP Basic Authentication headers to understand credentials, or encode username:password combinations for API authentication.
JWT Token Inspection
Decode the header and payload sections of JWT tokens (which are Base64-encoded JSON) to inspect claims, expiration times, and token structure.