About Base64 Encoder / Decoder
Base64 encoding is used everywhere in web development: embedding images in CSS and HTML, encoding JWT tokens, transmitting binary data through text-based protocols, storing binary data in JSON, and encoding email attachments. Our free Base64 Encoder / Decoder handles both text and binary files with one click — all in your browser.
Base64 converts binary data (like images or files) into a safe ASCII text string that can be transmitted over text-only channels like email, JSON payloads, and URL parameters. It's also used in HTTP Basic Authentication (credentials are Base64-encoded, not encrypted), JWTs (header and payload are Base64URL-encoded), and CSS data URIs (small images embedded directly in stylesheets).
Our tool encodes plain text strings, URL-safe Base64 (Base64URL for JWTs and URLs), and binary files. For developers: paste a JWT and decode all three parts (header, payload, signature) to inspect claims. For designers: convert a small SVG or PNG to a data URI for embedding directly in CSS without an HTTP request.
How to Use the Base64 Encoder / Decoder
Choose mode
Select 'Encode' to convert text to Base64, or 'Decode' to convert Base64 back to text.
Enter input
Type or paste text, or upload a file for binary Base64 encoding.
Copy result
The encoded/decoded output appears instantly. Copy with one click.
Key Features & Highlights
Common Use Cases
- Encode text to Base64 for HTTP Basic Auth headers
- Decode JWT tokens to inspect header and payload claims
- Encode images to Base64 data URIs for CSS embedding
- Encode file contents for JSON API payloads
- Decode Base64 API responses to readable text
Frequently Asked Questions
No — Base64 is encoding, not encryption. It transforms data into a different representation but provides no security. Anyone can decode Base64 instantly. For security, use actual encryption (AES, RSA) before Base64-encoding.
Base64 increases size by approximately 33% (every 3 bytes becomes 4 characters).
Standard Base64 uses + and / characters which have special meaning in URLs. Base64URL replaces + with - and / with _ to produce URL-safe strings, which is why JWTs use Base64URL.
Yes, 100% free with no hidden fees, subscriptions, or account requirements.
Everything runs client-side directly inside your web browser. No files, texts, or parameters are sent to our servers.
Yes, our tools are fully responsive and work seamlessly on iPhones, iPads, Android smartphones, and tablets.