Free · Browser-Only · No Server Upload

Base64 Encode and
Decode Online

The fastest, most private Base64 tool on the web. Convert text, URLs, and files in milliseconds your data never leaves your device.

Input0 chars
Output0 chars
∞
Free Forever
0ms
Server Latency
100%
Private & Secure
3
Encoding Modes
How It Works

Three Steps to Done

No signup, no configuration, no tracking. Open the tool and go.

1

Paste or Upload

Type text directly, paste from clipboard, or drag-and-drop any file into the upload zone.

2

Choose Mode

Pick standard encoding, decoding, or URL-safe mode depending on your use case.

3

Copy & Use

Instantly copy the result to clipboard or download it as a text file to use anywhere.

Why Choose Us

Everything You Need

A complete Base64 toolkit built for developers, designers, and everyday users alike.

🔒

100% Private

All processing happens in your browser. Zero server contact works fully offline after the page loads.

⚡

Instant Results

No waiting, no spinners. Results appear immediately using native browser JavaScript APIs.

📁

File Encoding

Encode any file images, PDFs, audio to Base64 with drag and drop. Supports up to 10 MB.

🔗

URL-Safe Mode

Converts + and / to URL-safe - and _, strips padding. Perfect for JWT and OAuth workflows.

🌐

Unicode Support

Full Unicode including emoji, CJK, and Arabic via proper UTF-8 encoding with the TextEncoder API.

📋

One-Click Copy

Copy Base64 output to clipboard instantly. Download results as .txt files for offline use.

Why It Matters

Real Benefits, Zero Compromise

Built around what developers and users actually need speed, privacy, reliability.

🛡️
Privacy First

Your Data Never Leaves Your Device

Unlike cloud based tools that process your input on remote servers, every encoding and decoding operation runs entirely in your browser. Sensitive credentials, tokens, and documents stay completely local no logs, no traces, no third parties.

🚀
Performance

Millisecond Response, Every Time

No round trips to a server means no network latency. Results appear the instant you click, regardless of your internet connection speed. The tool even works fully offline after the initial page load ideal for on-the-go developers.

🌍
Compatibility

Handles Any Language, Any File

Full Unicode support means emoji, Arabic, CJK, and every other character set works flawlessly. File encoding handles images, PDFs, audio, and any binary format up to 10 MB far beyond what many tools support.

⚙️
Developer Ready

Three Modes Built for Real Use Cases

Standard Base64 for general encoding, File mode for binary assets, and URL safe mode (RFC 4648 §5) for JWT, OAuth, and API work no need to juggle multiple tools or write one off scripts. Everything you need in a single interface.

Examples

See It in Action

Common Base64 encoding and decoding examples you can copy and use right away.

Simple Text Encoding

Text → Base64
Plain Text Input
Hello, World!
→
Base64 Output
SGVsbG8sIFdvcmxkIQ==

HTTP Basic Auth Header

Credentials → Base64
Username:Password
admin:s3cr3tPass!
→
Authorization Header Value
Basic YWRtaW46czNjcjN0UGFzcyE=

URL-Safe Base64 (JWT / OAuth)

URL-Safe Encoding
JSON Payload
{"sub":"1234","name":"Alice","iat":1516239022}
→
URL-Safe Base64 (no padding)
eyJzdWIiOiIxMjM0IiwibmFtZSI6IkFsaWNlIiwiaWF0IjoxNTE2MjM5MDIyfQ

Emoji & Unicode Text

Unicode → Base64
Unicode Input
こんにちは 🌍 مرحبا
→
Base64 Output (UTF-8)
44GT44KT44Gr44Gh44GvIPCfjI0g2YXYsdit2KjYpw==

Inline Image Data URI

File → HTML Embed
Usage in HTML
<img src="data:image/png;base64,…encoded…" alt="Embedded"/>
→
Result
Image renders without any HTTP request perfect for icons, email templates, and offline HTML pages.
Use Cases

Built for Real Workflows

From API development to email attachments, Base64 powers more of the web than you think.

01

Embedding Images in HTML & CSS

Convert images to Base64 Data URIs to embed them in <img> tags or CSS, eliminating extra HTTP requests and improving page load speed.

02

JWT Token Inspection

JSON Web Tokens use Base64URL encoding for header and payload. Decode them to inspect claims, expiry times, and issuer data during API debugging.

03

Email Attachments (MIME)

The MIME standard requires binary attachments to be Base64 encoded. Encode files for MIME messages or debug encoded email content.

04

API Credentials & Auth Headers

HTTP Basic Auth transmits credentials as a Base64 encoded user:pass string. Encode or decode them safely for testing API endpoints.

05

Environment Variables & Config

Store certificates or JSON configs as Base64 in env vars encode complex objects to a single string that survives shell escaping.

06

Binary Data in JSON APIs

JSON doesn't natively support binary. Base64 encode PDFs, audio, or icons to safely transmit them inside JSON request or response payloads.

What is Base64?

The Encoding Standard That Powers the Web

Base64 is a binary-to-text encoding scheme representing binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It allows binary content to be safely transmitted over text-only systems.

Every 3 bytes of input are converted into 4 Base64 characters roughly 33% larger than the original. The encoded string is safe in HTTP, SMTP, and JSON protocols.

The URL-safe variant (RFC 4648 §5) replaces + with - and / with _, making it safe in URLs and filenames. Widely used in JWT and OAuth 2.0 flows.

// Standard Base64 in JavaScript
 
const input = "Hello, World!";
 
// Encode → Base64
const enc = btoa(input);
// "SGVsbG8sIFdvcmxkIQ=="
 
// Decode → plain text
const dec = atob(enc);
// "Hello, World!"
 
// URL-safe (RFC 4648 §5)
enc.replace(/\+/g,'-')
.replace(/\//g,'_')
.replace(/=+$/,'');
FAQ

Frequently Asked Questions

Everything you need to know about Base64 encoding and this tool.

No. Base64 is an encoding scheme, not encryption. It's fully reversible and provides zero confidentiality. Anyone with the string can decode it immediately. Use encryption (AES, RSA) alongside encoding for security.
Absolutely not. This tool runs entirely in your browser using native JS APIs. Nothing is transmitted to any server. It even works offline after the page has loaded.
Base64 processes input in 3-byte groups. If the input isn't divisible by 3, = padding is appended to reach a multiple of 4 characters. One = = 1 padding byte; two == = 2 padding bytes.
Standard Base64 uses + and / which conflict with URL syntax. URL-safe Base64 (RFC 4648 §5) swaps + for - and / for _, and omits padding making it safe for query params, path segments, and cookie values.
Yes. Use the File tab to drag-and-drop or browse any file. The tool generates the Base64 string, which you can use as a data URI (data:image/png;base64,...) to embed images directly in HTML or CSS.
Yes. We use TextEncoder / TextDecoder to first convert to UTF-8 bytes before applying Base64, ensuring full Unicode support including emoji, CJK, and Arabic something basic btoa() can't handle alone.