Base64 Encoder / Decoder
Encode and decode Base64 strings instantly — no data sent to server.
About Base64 Encoder / Decoder
Free online Base64 encoder and decoder. Convert any text, URL, or data to Base64 encoding, or decode Base64 back to plain text. Runs 100% in your browser for maximum privacy. Used in email attachments, HTTP headers, data URIs, and API authentication.
Our Base64 encoder/decoder runs entirely in your browser. This is critical for sensitive use cases — your API keys, authentication tokens, and private data are never sent to our servers. The tool handles UTF-8 text correctly, which many online converters fail to do.
How to Use Base64 Encoder / Decoder
- 1Choose your mode: 'Encode' to convert text to Base64, or 'Decode' to convert Base64 back to text.
- 2Paste your input text or Base64 string into the text area.
- 3Click 'Encode to Base64' or 'Decode Base64' to process your input.
- 4The result appears below. Click 'Copy' to copy it to your clipboard.
- 5For decoding, paste any Base64 string (with or without padding characters '==') and click Decode.
Key Features
Use Cases for Base64 Encoder / Decoder
Email Attachments & MIME
Email protocols can only send ASCII text. Base64 encodes binary files (images, PDFs, audio) into ASCII so they can be safely transmitted as email attachments.
Data URIs for Web Development
Embed small images directly in HTML/CSS using data URIs: data:image/png;base64,[encoded-data]. This eliminates an HTTP request, useful for icons and small decorative images.
Basic Authentication Headers
HTTP Basic Authentication sends credentials as Base64: Authorization: Basic [base64(username:password)]. Use our encoder to generate auth headers for API testing.
Encoding JSON Web Tokens (JWT)
JWT tokens consist of three Base64-encoded sections (header.payload.signature). Use our decoder to inspect the header and payload sections of any JWT token for debugging.
Remember: Base64 is encoding, not encryption. Anyone can decode a Base64 string without a key. Never use Base64 to 'hide' sensitive data — use proper encryption (AES-256) for security. Base64 increases data size by approximately 33%.
Frequently Asked Questions
What is Base64 encoding?
Base64 converts binary data into ASCII text using 64 printable characters. It's used when binary data needs to be stored or transmitted over media designed to handle text.
Is Base64 a form of encryption?
No. Base64 is encoding, not encryption. Anyone can decode a Base64 string without any key. Never use it to secure sensitive data — use proper encryption for that.
Get the Best AI Tools,
Every Week
New AI tools, exclusive comparisons, and income strategies — delivered every Tuesday. Join 5,000+ creators and marketers who read it.
No spam. Unsubscribe anytime. We respect your privacy.