Encode text to Base64 (RFC 4648) and decode it back - UTF-8-safe, with a URL-safe variant, locally in your browser, with no upload.
Running locally on your device ...
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Base64 represents arbitrary data using only 64 printable characters. That is useful for embedding text or small content where only simple characters are allowed - such as in data URLs, JSON fields, configurations or email headers. This tool encodes your text to Base64 and decodes Base64 back into readable text.
You choose the direction: text to Base64 or Base64 to text. The text is encoded via its UTF-8 bytes, so umlauts, accents and emojis are preserved correctly. Unlike a file tool, this one works directly with pasted text - ideal for quick conversions without the detour via a file.
A toggle switches to URL-safe Base64 (RFC 4648 section 5): "+" becomes "-", "/" becomes "_", and the "=" padding is dropped. That lets you drop the result straight into a URL, a filename or a cookie value without percent-encoding it further. When decoding, the tool uses whichever alphabet matches the toggle you have set.
The whole conversion runs entirely locally in your browser in pure JavaScript - your text is not uploaded, not stored, and no foreign library is loaded from a CDN. If the Base64 input is invalid when decoding, the tool says so honestly instead of inventing a wrong result.
Many online Base64 tools send your text to their server to encode it - inconvenient for confidential values such as API keys or credentials, which are often transported as Base64. This tool encodes and decodes strictly locally in the browser, with no account and no character limit.
| Input formats | Text input |
|---|---|
| Output format | TXT |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: It uses Base64 (RFC 4648) over the UTF-8 bytes of the text, either the standard alphabet (+ /, with padding) or the URL-safe alphabet (- _, without padding). For whole files there are the dedicated encode and decode file tools. When decoding, valid Base64 in the matching alphabet is required, otherwise the tool reports an honest error. Very large texts are limited by your device memory.
No. The conversion runs entirely locally in your browser; your text never leaves your device and is not stored.
Yes. The text is encoded via its UTF-8 bytes, so umlauts, accents and emojis are preserved when converting back and forth.
This tool works with pasted text; for whole files (images, documents) use the dedicated encode and decode file tools.
When decoding, the tool reports an honest error instead of producing a wrong result. Check that the input is complete Base64 in the right alphabet (standard or URL-safe).
The RFC 4648 section 5 variant: "+" and "/" would have a special meaning in a URL, so it replaces them with "-" and "_" and drops the "=" padding character. That lets you drop the result straight into a URL path, a query or a filename.
Yes, in any current mobile browser just like on desktop - the text stays local.
No. No account, no artificial character limit - only your device memory sets a boundary for very long texts.
Yes. Unlike many online tools, your text is not sent to a server - try airplane mode.
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