Question 1

Is this Base64 tool free?

Accepted Answer

Yes, completely. Every feature on this page is free, including file and image encode/decode, inline preview, every Base64 variant, all ~27 legacy character sets, batch line decoding, and the Data URI/HTML/CSS snippet generator. There's no sign-up, no ads, and nothing held back behind a "Pro" tier.

Question 2

Do I need to download or install anything?

Accepted Answer

No. Everything runs in this browser tab. Paste text, or drop a file or image onto the page, and there's nothing to install and nothing left behind when you close it.

Question 3

Does this tool upload my data anywhere?

Accepted Answer

No. Every conversion, text, files, and images, in both directions, runs entirely in your browser using the Web platform's own encoding APIs. This tool doesn't even have a server to upload to, so whatever you convert here, including auth tokens or API payloads, never leaves your device.

Question 4

What is Base64 encoding?

Accepted Answer

Base64 is a way of representing arbitrary binary data, like an image, a PDF, or raw bytes, as plain, readable text using only 64 safe characters (A–Z, a–z, 0–9, + and /). It's used to safely embed binary data inside text-only formats like JSON, XML, email, or a CSS/HTML data URI, at the cost of inflating the size by roughly a third.

Question 5

Is Base64 encryption?

Accepted Answer

No. Base64 provides zero secrecy. Anyone can decode a Base64 string back to its original form instantly, including with this very page, since it's a reversible encoding, not a cipher. It's sometimes used to obscure data at a glance (which is why it shows up in malware and phishing payloads), but it should never be relied on to protect anything sensitive.

Question 6

How do I decode a Base64 string?

Accepted Answer

Switch to Decode, paste your Base64 string (or a full `data:...;base64,...` URI), and the result appears instantly as text below. No separate "Convert" button. Switch the data type to File / Image instead if you're decoding back to a file or picture.

Question 7

How do I encode text to Base64?

Accepted Answer

Switch to Encode, then type or paste your text. The Base64 output appears instantly below. Choose a different character set first if your text isn't UTF-8.

Question 8

Can I convert an image to Base64?

Accepted Answer

Yes. Switch the data type to File / Image, then upload or drag and drop your image. Its Base64 output appears instantly, along with a ready-to-use Data URI and HTML/CSS embed snippet.

Question 9

Can I decode Base64 back into an image or file?

Accepted Answer

Yes. Switch to Decode and File / Image, then paste the Base64 (a bare string or a full data URI both work). If it's a previewable image or PDF, you'll see it rendered directly on the page, not just a download link.

Question 10

What does the `=` at the end of a Base64 string mean?

Accepted Answer

It's padding, not data. Base64 always groups input into chunks of 3 bytes, and `=` fills in the gap when the last chunk has only 1 or 2 bytes left over, so the output length stays a clean multiple of 4 characters. You can safely turn on "No padding" when encoding if you don't need it; this tool decodes correctly either way.

Question 11

What is Base64URL, and when do I need it?

Accepted Answer

Base64URL is a small variant that swaps the standard `+` and `/` characters for `-` and `_`, since `+` and `/` have special meaning inside a URL or filename. Turn on "Base64URL" when encoding for a URL, filename, or JWT segment; when decoding, this tool detects and handles either alphabet automatically, so you never need to tell it which one you're pasting.

Question 12

Can I get a Data URI or an HTML/CSS snippet from an image?

Accepted Answer

Yes. Encoding or decoding a file/image both show a ready `data:` URI plus a copy-paste `<img>` tag and CSS `background-image` snippet underneath, so you can embed the image directly in HTML or CSS with nothing else to write.

Question 13

Can I convert Base64 to hex?

Accepted Answer

Yes. Decoding shows a "Base64 ↔ Hex" section with the exact bytes your Base64 decodes to, rendered as hexadecimal.

Question 14

Can I decode multiple Base64 strings at once?

Accepted Answer

Yes. Turn on "Decode each line separately" while decoding text, paste one Base64 string per line, and each line decodes independently below, with its own result or error.

Question 15

Why is my Base64 string invalid?

Accepted Answer

This tool checks for the three most common causes and tells you exactly which one applies: an invalid character outside A–Z, a–z, 0–9, +, /, -, and _; padding (`=`) placed somewhere other than the very end; or a length that isn't mathematically possible for Base64. You'll see the specific problem and, where relevant, its exact position, not a raw exception.

Question 16

Can I share a link to my conversion?

Accepted Answer

Yes. Share compresses your current text-mode conversion directly into the link itself and copies it to your clipboard; opening that link loads the same content straight back in, with nothing ever stored on a server. Very large conversions won't fit in a link at all: past a clear size limit, this tool says so honestly instead of handing out a link that silently breaks, and Download or Copy still work at any size.

Question 17

Is this a browser extension?

Accepted Answer

No. This is a website, not an installable browser extension, so there's nothing to add to Chrome or any other browser. If you specifically need a Base64 decoder inside your browser toolbar, that's a different kind of tool; this page covers the same paste-and-convert job with nothing to install.

Question 18

Does this work on mobile, and in every browser?

Accepted Answer

Yes. Encoding, decoding, file/image upload, every Base64 variant, all legacy character sets, batch mode, and the Data URI/hex tools all work on any modern browser, desktop or mobile: Chrome, Firefox, Edge, and Safari all handle it. Inline PDF preview depends on your browser's own built-in PDF viewer; if yours doesn't show one, Download still works.

Base64 Decode & Encode

Base64 ↔ Hex

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