Convert text to Base64 or decode Base64 back to readable text — instantly, privately, and for free.
Ctrl+Enter EncodeShift+Enter Decode
Input: 0 chars
Input Text0 chars
Ready
Output Result0 chars
—
What Is Base64 Encoding?
Base64 encoding is a method of converting binary data — or any sequence of bytes — into a string of printable ASCII characters. The name "Base64" comes from the 64-character alphabet used in the encoding: the 26 uppercase letters A–Z, 26 lowercase letters a–z, the digits 0–9, and the symbols + and /. An equals sign = is used as padding.
The encoding works by taking every 3 bytes of input (24 bits) and splitting them into four groups of 6 bits each. Each 6-bit group maps to one of the 64 characters. This means every 3 bytes of input becomes exactly 4 characters of Base64 output — an increase of approximately 33% in size.
Example
Text: Hello
Base64: SGVsbG8=
Base64 is not encryption — it is a lossless encoding that can be reversed by anyone who knows the algorithm. Its purpose is compatibility, not security: it converts binary data into a format that can safely pass through text-only channels without being corrupted.
Why Base64 Encoding Is Used
Web Development
Base64 is used extensively in web development to embed binary assets directly into HTML, CSS, or JavaScript as data URIs. A small image can be encoded as Base64 and embedded in an <img src="data:image/png;base64,..."> tag, eliminating a separate HTTP request.
Email & MIME
Email protocols were originally designed for plain ASCII text. Base64 allows email systems to attach binary files (images, PDFs, executables) by encoding them as ASCII text within the MIME format. This is why email attachments appear as long strings of characters in raw email source.
APIs & Data Transfer
Many web APIs transmit binary data — cryptographic keys, certificate data, file content, binary tokens — through JSON or XML, which are text formats. Base64 encoding is the standard way to include binary data in these text-based API payloads without corruption.
Authentication
HTTP Basic Authentication sends credentials as a Base64-encoded string in the Authorization header: Authorization: Basic dXNlcjpwYXNz. Note that this is Base64 encoding, not encryption — it provides no security without HTTPS.
Common Uses of Base64
🖼️
Inline Images
Embed small icons or images directly in HTML/CSS as data URIs to reduce HTTP requests and improve page load times.
🔑
API Keys & Tokens
Encode authentication credentials, API keys, and JWT headers/payloads for safe transmission in HTTP headers and JSON bodies.
📧
Email Attachments
MIME email protocol uses Base64 to encode binary file attachments so they can be safely carried in text-based email messages.
🔐
Cryptography
Public keys, certificates (PEM format), and cryptographic hashes are commonly stored and transmitted as Base64-encoded strings.
📦
Data Serialization
Binary blobs, file content, and byte arrays embedded in JSON, XML, or database records use Base64 for safe text representation.
🌐
URLs
Base64URL (a variant using - and _ instead of + and /) safely encodes binary data for use in URL query parameters and file names.
How to Use the Base64 Encoder / Decoder
To encode text to Base64: Paste or type your plain text in the Input panel on the left. Then click "Encode to Base64". The Base64 encoded string appears instantly in the Output panel.
To decode Base64 back to text: Paste your Base64 string into the Input panel. Click "Decode from Base64". The original readable text appears in the Output panel.
Use Auto mode: Toggle the "Auto encode / decode" switch at the top. The tool will automatically detect whether your input is plain text or Base64 and apply the correct operation in real time as you type.
Paste from clipboard: Click the Paste button to pull text directly from your clipboard into the input area, without manually pressing Ctrl/Cmd+V.
Swap panels: Click Swap to move the output into the input area for chaining operations — useful for double-encoding or encoding an already-encoded string.
Copy your result: Click Copy to copy the output to your clipboard with one click. Use the keyboard shortcut Ctrl+Enter to encode or Shift+Enter to decode without lifting your hands from the keyboard.
Benefits of Using an Online Base64 Tool
⚡
Instant Results
Encode or decode in milliseconds — no server round-trip, no latency, no waiting.
🔒
100% Private
All encoding/decoding runs locally in your browser. Your data never leaves your device.
🎯
Input Validation
Automatically detects invalid Base64 strings and shows clear error messages before you waste time debugging.
📊
Character Counter
Live character counts on both panels help you understand encoding size expansion (Base64 adds ~33% to size).
📱
Mobile Ready
Fully responsive with stacked panels and full-width buttons on phones and tablets.
🆓
Always Free
No account, no subscription, no usage limits. Open the page and start encoding immediately.
Frequently Asked Questions
Base64 encoding converts binary or text data into a string of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It works by taking 3 bytes of input and mapping them to 4 output characters. It is used to safely represent binary data in text-based systems like JSON, XML, email, and HTTP headers — without the data being corrupted or misinterpreted.
No. Base64 is encoding, not encryption. It does not use a key, it does not protect your data, and anyone can decode it in seconds. Base64 encoded data is completely readable to anyone who decodes it. Never rely on Base64 for security or privacy. If you need to protect data, use proper encryption algorithms like AES.
Paste or type your text in the Input panel and click "Encode to Base64". The encoded string appears immediately in the Output panel. You can also use the keyboard shortcut Ctrl/Cmd + Enter to encode without clicking the button, or enable Auto mode to encode in real time as you type.
Yes. Paste a Base64 string into the Input panel and click "Decode from Base64". The original text is recovered and displayed. The tool also validates your Base64 input — if the string is invalid (wrong characters, incorrect padding), a clear error message appears before attempting decode.
Yes, completely free with no registration, no subscription, no usage limits, and no software download. EasyTools provides this as a free public developer tool for anyone who needs to encode or decode Base64 data quickly.
Yes. The tool is fully mobile-responsive. On smartphones, the two panels stack vertically and all buttons become full-width for easy tapping. You can paste Base64 or plain text from your phone's clipboard and copy results back — all without any app installation.
All EasyTools
Explore our complete suite of free developer and productivity tools.