Base64 Encoder & Decoder
Secure, client-side Base64 converter for text and images. Encode images into ready-to-copy HTML/CSS inline snippets or parse Base64 data back to raw formats instantly.
Drag & Drop Image
Supports JPG, PNG, WebP, SVG
What is Base64?
Base64 is a binary-to-text encoding scheme that translates raw binary data (0s and 1s) into standard ASCII printable characters. By partitioning every 24 bits into four 6-bit chunks, it maps binary payloads securely to a safe 64-character index set.
Core Features
Our tool runs entirely client-side inside your browser with 100% data privacy. It features instant text conversions, responsive image-to-base64 encoders with pixel dimension readers, standard HTML/CSS snippet wrappers, and automated URL-safe conversions.
Why Use Base64?
It guarantees safe data transmission over networks that only support raw text formats (like emails, XML feeds, or JSON databases). Inline base64 assets allow you to embed images directly into HTML/CSS files, reducing extra HTTP network requests.
JWT, Base64, and URL Encoding Explained
Demystify data encoding formats. Learn how JSON Web Tokens work, when to use Base64, URL encoding, Hex, Binary, and Unicode standards to transmit and structure backend data safely.
Read the Complete Guide➔
🔒 Base64 Encoding Mechanics: RFC 4648 & Radix-64 Representation
Base64 is a binary-to-text encoding scheme standardized under RFC 4648 designed to represent binary payloads (such as images, PDF files, cryptographic hashes, and encryption keys) using an ASCII-safe 64-character alphabet (A–Z, a–z, 0–9, +, and /).
1. 24-Bit to 4-Character Mapping
Base64 partitions every 3 bytes (24 bits) of raw binary data into four 6-bit chunks. Each 6-bit value (0 to 63) maps directly to one character in the Base64 alphabet table.
2. The 33% Size Overhead
Because 3 bytes are expanded into 4 characters, Base64 encoding inherently increases data footprint by approximately 33%. Keep this in mind when embedding large data URIs in CSS.
3. URL-Safe Base64 (base64url)
Standard Base64 contains + and /, which have reserved meanings in URL parameters. URL-safe Base64 replaces + with - and / with _, and often omits padding.
⚡ Code Examples: Encoding & Decoding Across Environments
| Language | Encode | Decode |
|---|---|---|
| Browser JS | btoa('Hello') | atob('SGVsbG8=') |
| Node.js | Buffer.from(s).toString('base64') | Buffer.from(b, 'base64').toString() |
| Python | base64.b64encode(b) | base64.b64decode(s) |
| Linux CLI | echo -n "text" | base64 | echo -n "dGV4dA==" | base64 -d |
❓ Frequently Asked Questions — Base64 Studio
QIs Base64 a form of encryption?
Is Base64 a form of encryption?
No! Base64 is an encoding format, not encryption. Anyone can decode a Base64 string instantly without a key. Never use Base64 alone to protect confidential passwords or secrets.
QWhat do the trailing equals signs (=) mean?
What do the trailing equals signs (=) mean?
The equals character is a padding marker. When the original input byte count is not divisible by 3, one or two = characters are appended to ensure the encoded output length is a multiple of 4.
QCan I encode binary files (images, audio, PDF) directly?
Can I encode binary files (images, audio, PDF) directly?
Yes. Switch to the 'File to Base64' tab to drag-and-drop any image, SVG, or document and generate a valid data:image/png;base64,... data URI.
QAre my files uploaded to your server when encoding?
Are my files uploaded to your server when encoding?
No. NexTools processes all files locally via your browser's FileReader API. Your documents and text strings never leave your device.