Free Base64 Encoder/Decoder

The Base64 Encoder/Decoder is a free online tool that encodes text to Base64 format and decodes Base64 strings back to readable text.

Yes, it is completely free with no registration required. All encoding and decoding happens client-side in your browser.

Base64 encoding is used to safely transmit binary data as text in emails, URLs, APIs, and data URIs for embedding images in HTML/CSS.

Absolutely. The Base64 Encoder/Decoder processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the Base64 Encoder/Decoder is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Base64 Encoder/Decoder in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Base64 Encoder/Decoder works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

Standard Base64 uses the 64-character alphabet A-Z, a-z, 0-9, plus the symbols + and /, with = for padding. The trouble is that +, /, and = all have special meaning in URLs and aren't valid in filenames, so a standard Base64 string can break when placed in a query parameter or path. URL-safe Base64 fixes this by swapping + for - and / for _, and usually dropping the trailing = padding. The decoded data is identical; only the alphabet changes. This URL-safe variant is what JWT tokens and many web APIs use. This tool offers both: pick the URL-safe option to encode, and on decode it auto-reverses the substitution and restores padding so the string decodes cleanly. Toggle URL-safe above before encoding.

Base64 represents data using only 64 printable characters, so it has to spread the bits across more characters than the raw bytes would need. Specifically, every 3 bytes of input are regrouped into four 6-bit chunks and mapped to four Base64 characters. That 3-to-4 ratio means the encoded output is roughly 33% larger than the source, plus a few extra characters for = padding when the input length isn't a multiple of three. The size increase is expected and unavoidable, which is why Base64 suits small payloads like inline images or credentials rather than large files. This tool reports the input size, output size, and overhead percentage for each conversion, so you can see the exact growth. Paste your text or drop a file above to encode it and check the size stats.

No. Base64 is an encoding, not encryption, and it adds no security whatsoever. It simply rewrites bytes using a public 64-character alphabet so binary data can travel safely through text-only systems like email and JSON. Anyone can reverse a Base64 string back to its original content instantly with no key, password, or secret involved, exactly the way this decoder does. A string that looks scrambled is therefore not protected; encoding a password in Base64 is the same as storing it in plain text. If you need to keep data confidential, use real encryption such as AES and then, if required, Base64-encode the encrypted bytes for safe transport. Use this tool to encode or decode for compatibility and data transport, but never rely on it to hide sensitive information.

Some systems can't handle one continuous, very long line of Base64. The classic example is email: the MIME standard wraps encoded attachments into fixed-width lines, typically 76 characters, so older mail servers and clients don't choke on them. That's why a Base64 blob copied from an email source or PEM certificate often appears as many short lines rather than a single string. The line breaks are not part of the data; decoders ignore the whitespace and reconstruct the original bytes regardless. This tool lets you control wrapping directly: enable line wrapping to break output at the MIME default of 76 characters, or set any column width from 1 to 200 to match a target format. When decoding, pasted line breaks are handled automatically. Adjust the wrap option above before you copy your encoded result.

A data URI lets you place an image directly inside HTML or CSS instead of linking to a separate file, which removes one HTTP request for small graphics like icons. The format is data:[mime-type];base64,[encoded-data] -- for example data:image/png;base64, followed by the encoded bytes. To build one, drop your image file into the encoder, which reads the file, encodes it, and can emit the full data URI for you including the correct MIME type. You then paste that string into an img tag's src attribute or a CSS background-image url(). Keep in mind that Base64 adds about 33% to the file size, so data URIs are best for small assets; large images are better left as normal file references. On decode, this tool auto-detects a pasted data URI and renders the image back. Drop an image above to generate its data URI.