Free Base64 Encoder & Decoder Online
The best free base64 encoder and decoder online. Encode text to base64 or decode base64 strings back to plain text instantly.
Built With Care
“Uses the browser's built-in atob() and btoa() functions for standards-compliant encoding and decoding. Supports Unicode and handles multi-line strings.”
Base64 Converter & Developer Inspector
Encode plain text to Base64 or decode Base64 back to readable text. Uses the browser's native atob/btoa functions so nothing gets sent anywhere. Handles Unicode and emojis correctly.
- 1Toggle the mode to either 'Encode' (Text to Base64) or 'Decode' (Base64 to Text).
- 2Paste your source material into the input field. The tool handles multi-line strings effortlessly.
- 3Click the action button to perform the transformation instantly.
- 4Inspect the output for accuracy and use the copy button to transfer it to your clipboard.
- 5Use the 'Swap' button to quickly reverse the transformation or verify your results.
- Bidirectional Processing: Seamlessly switch between encoding and decoding with a single click.
- Developer-First Precision: Perfect for handling JWT parts, Basic Auth headers, and data URIs.
- Standard RFC 4648 Compliance: Compatible with all modern programming languages and web APIs.
- Client-side processing: No data is sent to external servers.
- Large Payload Support: Handles massive strings and complex JSON blobs without performance degradation.
Real Ways People Use This
API Development & Debugging
Quickly decode Basic Auth headers or inspect JWT payloads during backend troubleshooting and integration testing.
Data URI Generation
Encode small assets or SVG strings to create data URIs for CSS or HTML embedded images.
Email Header Inspection
Decode email subjects or body parts that are encoded in Base64 for transport across legacy systems.
Configuration Mangement
Safely encode config files or environment variables that need to be passed as single-line strings in CI/CD pipelines.
Cross-Language Data Passing
Standardize complex data formats into safely transportable ASCII strings for inter-service communication.
- Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string. Never use it to protect sensitive data without actual encryption.
- For binary data like images or files, use the dedicated Base64 Image Decoder tool for better results.
- 1Verify your input is valid UTF-8 text before encoding to avoid garbled output.
- 2Check for trailing '=' padding when decoding — it's normal and part of the RFC 4648 standard.