Base64 Decoder and Encoder — Encode or Decode Base64 Online

Paste your text or drop any file into the input box, keep the mode on Encode and the Base64 representation appears in the output. For files you get a data URL that can be embedded directly in HTML, CSS or JSON — no upload server in between.

URL-safe Base64 swaps "+" for "-" and "/" for "_" and strips the trailing "=" padding so the encoded value can travel inside URLs, filenames and JWT segments without further escaping. Toggle URL-safe whenever the output ends up in a query string, path segment or HTTP header.

No. Base64 is an encoding, not encryption. Anyone can decode the string in one click, so never use it as a secrecy mechanism. Reach for AES, RSA or libsodium when you need real confidentiality, and use Base64 only to make binary data text-safe.

Base64 packs three bytes into four characters. When the input length is not a multiple of three, the encoder pads the final block with "=" so the output stays a multiple of four. Standard Base64 keeps the padding; URL-safe Base64 drops it because the length is implicit.

Yes. The encoder reads the input as UTF-8 before encoding, so Arabic, Chinese, Cyrillic and emoji characters round-trip cleanly. The decoded result is rendered back as UTF-8 text, which is what every modern browser, terminal and API expects.

Base64 inflates payloads by roughly 33% — three bytes of input become four bytes of output. That is fine for short tokens, small icons and JSON-embedded thumbnails, but for large assets prefer a direct binary upload or a CDN link to keep transfers fast.

No. The encoder runs entirely inside your browser using the standard atob / btoa APIs plus a UTF-8 wrapper, so your text or file never reaches a server. That makes the tool safe for tokens, credentials and proprietary binaries you do not want to expose.

Switch the mode to Decode, paste your Base64 string, and the original text appears instantly in the output, ready to copy or download as .txt. If the string uses '-' and '_' instead of '+' and '/', turn on URL-safe so it decodes correctly.

Yes. Switch to Decode mode and paste the Base64 or data URL text — if it decodes successfully, a "Download as file" button appears next to the plain Download option. Clicking it writes out the exact original bytes with the extension detected from the embedded MIME type, so a base64-encoded photo or PDF comes back as a real, openable file instead of garbled text.

Download always saves the decoded output as a plain .txt file, which is right when the Base64 represents text. Download as file only appears when the decoded bytes are recognized as binary data — like an image or PDF — and it reconstructs the original file with its proper extension instead of dumping raw bytes into a text file that won't open correctly.

Paste the Base64 string or data URL, switch the mode to Decode, then use Download as file to save the original binary — a PDF, PNG, JPG or any other format. Decoding is byte-for-byte, so the file you get back is identical to the one that was encoded. It is the quickest way to turn base64 to pdf or base64 to image without installing anything.

Drop the image — PNG, JPG, SVG, anything — into the input and the encoder produces a data URL you can paste straight into an <img> src attribute or a CSS background-image. Because the data URL embeds the image bytes inline, the page makes no extra network request; just remember Base64 adds roughly 33% to the size, so keep inlined images small.

No — Base64 Encoder / Decoder runs entirely in your browser, so what you paste never leaves the machine you are on. That matters if you are checking something that contains a token, a key or customer data. Closing the tab is enough to clear it.

The error points at the first position that could not be parsed, which is usually just after the real mistake rather than on it — a missing comma, an unclosed quote or bracket, or a smart quote pasted in from a document instead of a straight one. Check the line above the reported position first.

No to both. Base64 Encoder / Decoder is free, your download carries no watermark, and nothing is asked for at the end — there is no point in the flow where you finish the work and then discover it costs money.

No — Base64 Encoder / Decoder runs in the browser on desktop and phone. There is nothing to install, no trial to start, and no license to buy before you can see whether it does what you need. Try it on the file you are actually stuck with rather than a sample.