Free Online Base64 Encoder & Decoder

Base64 turns binary data into text using 64 characters (A to Z, a to z, 0 to 9, + and /), so it can travel through email, JSON, HTML and HTTP headers that expect text. Common uses are data URIs, email parts, Basic Auth headers and API payloads.

Open the Decode tab, paste the string and click Decode or press Ctrl+Enter. The text appears in the output box. Line breaks, spaces and missing = padding are fine, but the result has to be UTF-8 text; binary data shows an error.

No. Base64 is an encoding, not encryption, so anyone can decode it without a key. Don't use it to hide passwords or secrets. To protect data, encrypt it; to get a fingerprint of a file or text, use a hash generator instead.

On the Encode tab, click Encode a file and pick any file, such as a PNG, PDF or font. The output box shows the raw Base64 without a data: prefix. Copy it from there, and don't click Encode again, which would encode the Base64 itself a second time.

Not yet. The decoder only outputs text, so Base64 of an image, PDF or ZIP shows an error instead of a download. To view an image, put data:image/png;base64, in front of the string and paste the whole thing into your browser's address bar.

Base64URL swaps + for - and / for _ and often drops the = padding, so the string is safe in links and file names. This tool reads and writes standard Base64 only. For JWT parts, which use Base64URL, the JWT decoder converts them for you.

The = signs at the end are padding that brings the length up to a multiple of 4. This tool always adds them when encoding, so delete them by hand if your system wants unpadded Base64. When decoding, missing padding is accepted.

Decoding fails when the string has characters outside the standard alphabet, such as - or _, starts with a data:...;base64, prefix, or holds bytes that aren't UTF-8 text, like an image or an old Latin-1 file. Delete the prefix, or change - to + and _ to /.

Yes, by about a third. Every 3 bytes become 4 characters, so a 3,000-byte file gives 4,000 characters of Base64. That is why data URIs suit small icons and fonts better than large photos, which load faster as normal files.

Yes. Text is turned into UTF-8 bytes before encoding, so é, 世界 and 😀 encode and decode back unchanged. The one exception is a broken emoji, half of a surrogate pair left over from bad copying, which can't be encoded and shows an error.

Your text and files are read in this browser tab and never sent to PixConvert. On the live site, analytics record clicks like Copy, the time a run took and a size range such as 0-100KB, never what you paste. Base64 still hides nothing, so treat the output like the original.