Base64 Encoder & Decoder
Encode and decode Base64 in real time — text or files, standard or URL-safe alphabet — without your data leaving the browser.
Asset Encoder
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Invalid Asset Data
Encode and decode Base64 in real time — text or files, standard or URL-safe alphabet — without your data leaving the browser.
Layerbit provides a robust, zero-latency Base64 processor. Whether you are encoding API payloads, embedding small images into CSS/HTML files, or decoding secure webhooks, this tool operates entirely within the DOM. No data is ever transmitted to a backend server.
When building full-stack web applications, especially within robust backend architectures like .NET, transporting raw binary files over JSON REST APIs can be complex. Converting binary streams into a Base64 string allows seamless serialization directly into standard JSON payloads for easier data transit.
Reduce HTTP requests on landing pages by converting lightweight icons, logos, or placeholder graphics into Base64 Data URIs. You can paste the resulting string directly into an HTML `<img src="...">` tag or as a CSS background-image.
JSON Web Tokens (JWTs) are heavily reliant on Base64Url encoding. Use the String Cryptography tab to quickly decode the payload section of authentication tokens to verify embedded user claims, expiration dates, and roles without needing specialized third-party tools.
Need to test the cipher? Click any of the sample payloads below to instantly load them into the engine and watch the real-time conversion.
Base64 is a binary-to-text encoding scheme that translates arbitrary binary data (like images, PDFs, or compiled code) into an ASCII string format. It translates the data into a radix-64 representation, using only 64 specific characters (A-Z, a-z, 0-9, +, and /) ensuring the data remains intact without modification during transport across systems that only support text.
No. This is a very common misconception. Base64 is strictly an encoding mechanism used for data translation and transport, not a security protocol. It does not use cryptographic keys, and anyone with access to the Base64 string can instantly decode it back to its original format. Never use Base64 to hide sensitive data or passwords.
Because Base64 uses a limited character set to represent binary data, it requires 4 standard ASCII characters to represent every 3 bytes of raw data. This mathematical conversion means that encoding any file into Base64 will automatically increase its overall size by approximately 33%. This is why it is best used for small assets rather than massive video or audio files.
Base64 (RFC 4648) regroups every three bytes of input — 24 bits — into four 6-bit chunks, each of which indexes a 64-character alphabet. Three bytes in, four characters out, which fixes the overhead at exactly 33% regardless of content. A 3 MB image becomes a 4 MB data URI, and the encoded form compresses worse than the original binary did.
That ratio is the main thing to know when deciding whether to inline an asset. Replacing one HTTP request with a third more bytes on every page load is often the wrong trade, and it is always worth measuring rather than assuming. Our Base64 guide goes into the arithmetic, the padding rules and the URL-safe variant in full.
= is forPadding. When the input is not a multiple of three bytes the output is padded to a multiple of four: one leftover byte gives two characters plus ==, two leftover bytes give three plus =. It carries no data — it only tells a streaming decoder where the input ended.
Standard Base64 uses + and /. In a query string, form decoding turns + into a space; in a path, / is a separator. Base64url substitutes - and _ and usually drops the padding, which is why JWT segments look the way they do.
Base64 encodes bytes. To encode a string you must first choose how it becomes bytes — almost always UTF-8. The browser's btoa() predates this and throws on any character above U+00FF, so accented letters, CJK text and emoji all fail without a TextEncoder step first.
Base64 has no key, no secret and no variability: the same input always produces the same output, and every decoder on earth reverses it instantly. It is worth being blunt about this because the mistake is so common and so consequential.
base64(user:password). Over plain HTTP that is a password in clear text — the encoding changes nothing an attacker cares about.If you need confidentiality you need encryption. If you only need to move bytes through a text-only channel, Base64 is exactly the right tool — and those are genuinely different problems.
The Base64 strings developers most often need to decode are the interesting ones: a token from a log file, a credential from a misconfigured header, a certificate body, an encoded payload from a bug report. Pasting those into a server-side decoder means handing the underlying secret to someone else's infrastructure. This tool runs entirely in the page — text and file input alike — so whatever you decode stays on your machine.
- and _), ignores line wrapping and whitespace, and tolerates missing padding, so JWT segments and copied-from-a-log strings decode directly. Encoding and decoding use TextEncoder/TextDecoder for correct UTF-8 on multi-megabyte input.