Base64 Encoder / Decoder
Text · Files · Images · URL-safe · MIME · PEM · Data URI — 100% local, no upload
Type or paste text to encode it, or import any file to get its Base64 representation. Decode Base64 or a Data URI in one click. Everything runs in your browser — no data is ever sent anywhere.
What is Base64 used for?
Base64 encodes binary data as ASCII text to transmit it in text-only contexts: emails (MIME), HTML src attributes (Data URI), JWT tokens, HTTP Authorization headers, Kubernetes secrets. Every group of 3 bytes becomes 4 characters — a ~33% size increase.
Features
- Real-time text → Base64 encoding
- Base64 → text decoding
- File import by button or drag-and-drop
- URL-safe variant (JWT, OAuth)
- MIME line wrap (76 chars)
- PEM line wrap (64 chars)
- Custom line length
- Optional padding
- UTF-8 or Latin-1
- File → Base64 Data URI
- Data URI → file download
- Image preview when decoding
- Copy without data: header
- Auto-detect mode
Frequently Asked Questions
What is Base64?
Base64 represents binary data as an ASCII string using 64 printable characters (A-Z, a-z, 0-9, +, /). It is ubiquitous in web protocols and data formats.
What is the difference between standard and URL-safe Base64?
The URL-safe variant (RFC 4648) replaces + with - and / with _, avoiding conflicts in URLs. Used in JWTs, OAuth 2.0, and file identifiers.
When should I use MIME or PEM line wrapping?
MIME (76 chars/line) is required by RFC 2045 emails. PEM (64 chars) is the standard for SSL/TLS certificates and SSH keys. No line wrap is fine for tokens and JSON APIs.
How do I convert an image to a Data URI?
Click Import file or drag your image into the input area. The tool generates a data:image/png;base64,… Data URI ready to paste into HTML or CSS. Use Copy without header to get the raw Base64 only.
Is my data private?
Absolutely. All Base64 processing runs in JavaScript in your browser. No data — text or file — is ever transmitted to a server.