Overview
Base64 shows up in surprising places: the images embedded in web pages, the tokens in your login headers, email attachments, the data URIs in CSS. It exists for one reason — to carry binary data through systems that only trust plain text. This tool performs the translation both ways, instantly.
The single most important thing to know about Base64 is what it is not: encryption. It is a costume, not a lock. Anyone can decode it in a second — including with this page. Treat Base64 as a transport format, never as security.
If it is not encryption, what is it for?
Some channels only tolerate a limited alphabet — letters, digits and a couple of symbols. Binary data (images, files, raw bytes) does not fit that alphabet, so Base64 re-packages every 3 bytes as 4 text characters from a safe 64-character set. The data gets about a third larger, but it survives email systems, headers and JSON strings intact.
That is why you meet it in data URIs (small images inlined in HTML), in HTTP Basic authentication headers, and in MIME email attachments. In each case the goal is the same: smuggle arbitrary bytes through a text-only channel without corruption.
Features
- Encode and decode modes on one page.
- Correct Unicode handling — emoji and non-Latin scripts survive the round trip.
- Live conversion as you type, no buttons to press.
- Padding handled properly (the = signs at the end).
- Copy result in one click for pasting into code or configs.
- Private: nothing you encode or decode leaves the page.
Benefits
- Read the unreadable: decode a token to see what it actually contains.
- Embed small assets by encoding them for data URIs.
- No mojibake: proper UTF-8 handling, not the broken kind.
- Instant answers with no installs or sign-ups.
Who can use it
Developers inspecting JWT tokens and auth headers, anyone embedding images as data URIs, QA engineers crafting test payloads, students learning how binary travels through text channels, and the generally curious decoding a suspicious-looking string. Just remember the golden rule before you “secure” anything with it.
How to use
- Choose Encode or Decode mode.
- Paste or type your text (or Base64) into the input.
- Read the converted result as it appears.
- Switch modes to verify the round trip.
- Copy the result when it looks right.
Frequently asked questions
Is Base64 encryption?
No — and this is the most common and most dangerous misunderstanding about it. Base64 is an encoding: a reversible, standardised, publicly documented transformation with no key and no secrecy. Decoding it takes one line of code. Never use it to hide passwords, tokens or anything sensitive; use real encryption for that.
Why does my Base64 end with = signs?
Padding. Base64 works in groups of 3 input bytes → 4 output characters; when the input is not a multiple of 3, = characters pad the last group out. One = means the input was 2 bytes short of a group, two == means 1 byte short. Decoders expect them, so keep them.
Why did my emoji turn into garbage?
Because naive Base64 works on bytes, and many simple implementations mangle multi-byte Unicode characters. This tool encodes proper UTF-8 first, so emoji, accented letters and non-Latin scripts survive the round trip intact.
What is a data URI?
A way to embed small files directly in HTML or CSS, like 
Can I decode something and get a file back?
The tool decodes to text. If the Base64 represents binary (like an image), you will see garbled characters — that is the raw bytes shown as text, which is expected. For file decoding you need a dedicated binary tool.
Conclusion
A costume for bytes, not a lock for secrets. Encode to transport, decode to inspect — and never confuse the two.