Base64 Decoder
Decode Base64 back into readable text, including URL-safe input and missing padding. It runs entirely in your browser — no signup, no installation, and nothing you paste or drop leaves your device.
Bad input is reported instead of turned into garbage: characters outside the alphabet, misplaced padding and impossible lengths all produce a message with the position. If the bytes are not valid UTF-8 — an image, a ZIP or encrypted data — the tool says so and shows the raw bytes in hex.
Decode Base64 Without Guessing
Base64 decoding is often done sloppily: a tool that does not check its input happily prints nonsense when the string is truncated or contains a typo. This decoder validates instead of guessing. It accepts the standard alphabet and the URL-safe variant from RFC 4648, with or without the trailing padding, and ignores line breaks and spaces — which is what you get when Base64 is copied out of an e-mail, a PEM file or a JSON log line. Characters outside the alphabet, padding in the middle and lengths that cannot be a Base64 sequence are rejected with the offending character and its position. After decoding, the bytes are checked against the UTF-8 rules, so you can tell whether the result really is text or binary data such as an image, a ZIP archive or ciphertext; if the bytes are not valid UTF-8 the tool says so and shows them as hex. Everything runs in the browser and nothing is uploaded.
Base64 dekodieren, ohne zu raten
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What is Base64 Decoder?
Base64 Decoder is a free online developer tool built for developers debugging payloads, configs and code. Decode Base64 back into readable text, including URL-safe input and missing padding In practice you paste the Base64 string, choose URL-safe input or automatic padding repair if needed, and then read and copy the decoded text.
Your code, tokens and payloads never leave the browser, which matters when you are debugging something under NDA or handling production data.
How to use Base64 Decoder
- Paste the Base64 string.
- Choose URL-safe input or automatic padding repair if needed.
- Read and copy the decoded text.
Base64 Decoder FAQ
Is Base64 Decoder free to use?
Yes. Base64 Decoder is completely free and needs no account, no trial and no payment details. Every feature on the page is available without limits.
Is my data uploaded anywhere?
No. Base64 Decoder runs entirely in your browser, so the text, file or number you enter never leaves your device.
Does Base64 Decoder work on a phone or tablet?
Yes. It works in any modern browser on desktop, tablet and phone. There is no app to install and no account to create.
How do I use Base64 Decoder?
Paste the Base64 string. Choose URL-safe input or automatic padding repair if needed. Read and copy the decoded text.