Base64 Studio
Convert text to Base64 strings or decode them instantly. 100% Client-side privacy.
Good to know — no surprises:
- Inputs over 5,000,000 characters are blocked on purpose, so a huge paste can't freeze your tab.
- The "looks like Base64" hint below is a pattern guess, not a certainty — it never decodes anything for you automatically.
- Decoding only produces text. If a Base64 string holds binary data (an image, a file, etc.), it will fail to show as text — that's expected, not a bug.
- Copy needs clipboard permission or HTTPS. We fall back to a manual-select method automatically, and tell you plainly if even that fails.
- Base64 is encoding, not encryption — anyone can reverse it instantly, so never use it to hide sensitive data.
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. By translating binary data into a radix-64 representation, Base64 ensures that data remains intact without modification during transport through text-based systems like email or HTML.
Data Integrity
Base64 is not encryption; it is an encoding. It makes data readable by machines, not hidden from humans.
Efficiency
Base64 encoding increases the data size by roughly 33% compared to the original binary data.
Developer Use
Commonly used for Data URIs (embedding images in CSS) and basic authentication headers in APIs.
Known Limitations
Inputs are capped at 5M characters, and the decoder only reconstructs valid UTF-8 text — Base64 of raw binary files won't display as text.
Base64 FAQ
Does this tool support special characters?
Yes. We use a robust URI-component handling method to ensure emojis and special UTF-8 characters encode and decode without "Malformed URI" errors.
Is my data stored on Rebrixe?
Never. The conversion happens strictly in your browser's memory using JavaScript. As soon as you close the tab, the data is gone.
Why does decoding sometimes fail on a string I know is valid Base64?
Because "valid Base64" and "valid text" are two different things. If the original data behind that Base64 was an image or another binary file, decoding it correctly produces raw bytes — and raw bytes usually aren't valid UTF-8 text, so we show an error instead of garbled characters. The Base64 wasn't wrong; it just wasn't text to begin with.
Why does Copy to Clipboard sometimes ask me to copy manually?
Clipboard access depends on your browser and whether the page is served over HTTPS. We try the modern clipboard API first, automatically fall back to an older copy method if that's blocked, and only ask you to select the text yourself if both methods fail — which can happen on some locked-down or outdated browsers.