Base64 Encode & Decode Online - Free Tool 2026

Fast, secure, 100% client-side Base64 converter. Encode text, images & files instantly. No signup, completely free.

🔒 100% Private ⚡ Instant 🆓 Free Forever 📱 Mobile Ready
Ad Space - 728x90
📤
Click or drag file
Max: 10MB

🔒 100% Client-Side

All processing in your browser. Data never leaves your device.

⚡ Powerful Features

Text, files, images up to 10MB. URL-safe mode. Batch processing.

Ad Space - 300x250

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that converts binary data into ASCII string format using 64 printable characters (A-Z, a-z, 0-9, +, /). It's essential for encoding data that needs to be stored or transferred over text-based protocols like HTTP, email, JSON APIs, and XML.

When to Use Base64?

  • Data URIs: Embed images in HTML/CSS without external files
  • API Communication: Send binary data over JSON/XML APIs
  • Authentication: HTTP Basic Auth encodes credentials
  • Email Attachments: MIME uses Base64 for files
  • JWT Tokens: JSON Web Tokens use Base64URL
  • Certificates: PEM format uses Base64 for SSL certs

How Does It Work?

Base64 encoding works by: 1) Dividing input data into 3-byte groups (24 bits), 2) Splitting into 4 groups of 6 bits each, 3) Mapping each 6-bit value to a Base64 character, 4) Adding padding (=) if needed. Important: Increases data size by ~33%.

How to Use This Tool

Encoding Text to Base64

  1. Click the "Encode" tab
  2. Select "Text" mode
  3. Type or paste your text
  4. See instant Base64 result
  5. Click "Copy"

Encoding Files

  1. Click "File / Image"
  2. Upload file (drag & drop or click)
  3. Get Base64 output instantly
⚡

Instant

Real-time encoding/decoding

🔒

Private

100% client-side processing

📁

Multiple Formats

Text, files, images up to 10MB

🌐

URL-Safe

RFC 4648 compliant

Real-World Use Cases

🖼️ Email Images

Embed images as Base64 in email HTML

🔑 API Auth

HTTP Basic Auth: Basic base64(user:pass)

🎫 JWT Tokens

JSON Web Tokens use Base64URL encoding

🎨 CSS Data URIs

Embed images in CSS to reduce requests

📦 JSON Files

Include binary files in JSON payloads

🔐 SSL Certs

PEM format uses Base64 encoding

Ad Space - 728x90

Code Examples

Learn Base64 in popular languages:

JavaScript

// Browser
const encoded = btoa('Hello');
const decoded = atob(encoded);

// URL-safe
const safe = encoded.replace(/\+/g,'-').replace(/\//g,'_').replace(/=/g,'');

Python

import base64

encoded = base64.b64encode(b'Hello')
decoded = base64.b64decode(encoded).decode()
url_safe = base64.urlsafe_b64encode(b'Hello')

PHP

$encoded = base64_encode('Hello');
$decoded = base64_decode($encoded);
$safe = strtr($encoded, '+/', '-_');

Java

String enc = Base64.getEncoder().encodeToString("Hello".getBytes());
byte[] dec = Base64.getDecoder().decode(enc);

Base64 vs Other Methods

Encoding Use Case Size Pros Cons
Base64 Binary to text +33% Widely supported Larger size
Hex Colors, hashes +100% Human-readable Double size
URL Query params Variable Preserves chars URL only

When NOT to Use

  • Large files: Use direct binary uploads
  • Security: Base64 is NOT encryption - use AES/RSA
  • Compression: Base64 doesn't compress - use gzip
Ad Space - 728x90

FAQ - Frequently Asked Questions

Base64 is a binary-to-text encoding using 64 printable characters (A-Z, a-z, 0-9, +, /). Used for encoding data in text-based protocols like HTTP, email, JSON, XML.

Yes! 100% client-side processing in your browser. No data sent to servers. Complete privacy and GDPR compliance.

Maximum 10MB. Ensures optimal browser performance while covering most use cases like images and documents.

URL-safe Base64 (RFC 4648) replaces + with - and / with _ to avoid URL conflicts. Padding = removed. Essential for URLs, filenames, JWT tokens.

Yes! Encode any file type (JPEG, PNG, GIF, SVG, WebP) up to 10MB. Use in data URIs: data:image/png;base64,[string]

NO! Base64 is encoding, not encryption. Zero security, easily reversible. For security use proper encryption (AES, RSA) before encoding.

Base64 increases size by ~33% (4/3 ratio) because it represents 3 bytes using 4 ASCII characters. Trade-off for text compatibility.

Upload image → encode → prepend data:image/png;base64,. Use in HTML or CSS backgrounds.

All modern browsers: Chrome, Firefox, Safari, Edge, Opera, Brave. Mobile versions too. Works on all platforms.

Processes each line separately for batch operations. Each input line produces one output line. Perfect for lists.

Base64 more efficient (+33%) than Hex (+100%). Use Hex for human-readable (colors). Use Base64 for efficiency.

NO! Never use for password security. Anyone can decode. Use HTTPS, bcrypt/Argon2 for storage, AES/RSA for encryption.

Yes! Supports Unicode, emoji, all international characters. UTF-8 encoding before Base64 conversion.

Yes! Completely free forever. No signup, no limits, unlimited usage. Ad-supported.

Yes! Once loaded, works offline. All client-side. Perfect for air-gapped environments.

Ad Space - 728x90