๐ Base64 Encoder
Encode and decode Base64 strings free online. Instant conversion for data URIs, APIs and tokens. Browser-based, no upload.
๐ Base64 Encoder
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About the Base64 Encoder Tool
Base64 encodes binary data using only 64 printable ASCII characters, which lets it travel safely through systems built for text โ email bodies, JSON payloads, URL parameters, and HTTP headers among them. Without it, arbitrary bytes would be corrupted by systems that interpret certain characters specially.
It is worth being clear that Base64 is an encoding, not encryption. Anyone can decode it in seconds, which is exactly what this tool does. Encoding and decoding both run entirely in your browser, so tokens and payloads are never transmitted.
How to Use Base64 Encoder
- Paste your text or Base64 string into the input area.
- Choose whether to encode or decode.
- Press Convert.
- Copy the result.
When to Use This Tool
- Decoding a JWT payload to inspect its claims during debugging
- Encoding credentials for an HTTP Basic Authorization header
- Creating data URIs for embedding small files inline
- Decoding Base64 content received from an API
- Encoding binary data for transmission through a text-only channel
Things Worth Knowing
- Base64 output is about 33% larger than the input, since it encodes three bytes as four characters.
- This is encoding, not encryption โ it provides no confidentiality whatsoever.
- URL-safe Base64 replaces + and / with - and _ to avoid conflicts in URLs.
Quick Facts
| Tool name | Base64 Encoder |
| Category | Utilities |
| Price | Free โ no account, no trial, no watermark |
| Where it runs | Entirely in your browser (client-side) |
| Files uploaded | None โ your data never leaves your device |
| File size limit | None imposed; limited only by device memory |
| Works offline | Yes, once the page has loaded |
| Platforms | Windows, macOS, Linux, Android, iOS |
Frequently Asked Questions
Is Base64 a form of encryption?
No, and treating it as one is a serious mistake. It is a reversible encoding with no key and no secret. Anyone can decode it instantly. Never use it to protect passwords or sensitive data.
Why is my encoded string longer than the original?
Because Base64 represents every three bytes as four characters, adding roughly 33%. That overhead is the cost of restricting output to a safe character set.
What are the equals signs at the end?
Padding. Base64 works in three-byte groups, and when the input length is not divisible by three, one or two = characters pad the final group.
Can I decode a JWT token here?
Yes. A JWT consists of three Base64url-encoded sections separated by dots. Decode the first two to read the header and payload. The third is a signature and will not decode to readable text.