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Base64 Decoder

What is Base64 Decoding?

Base64 decoding is the process of converting Base64-encoded data back to its original text or binary format. Base64 is an encoding scheme that represents binary data using only 64 printable ASCII characters, making it safe to transmit over text-based protocols like HTTP, email, or JSON. You'll encounter Base64 everywhere: embedded images in HTML/CSS data URIs, JWT tokens, API credentials in Authorization headers, and encoded file attachments. Decoding reverses the process, recovering the original bytes or text from the encoded string.

How to Use the Base64 Decoder

  1. Paste your Base64-encoded string into the input box.

  2. Click the "Decode" button — the decoded output appears instantly.

  3. If your string uses URL-safe Base64 (- and _ instead of + and /), the tool handles it automatically.

  4. Copy the decoded result using the output text area.

  5. If the result looks like garbled text, the original data may have been binary (an image or file) rather than plain text.

This free online Base64 decoder works entirely in your browser — no data is ever sent to a server. It supports both standard Base64 and URL-safe Base64 (RFC 4648). Perfect for developers debugging API responses, inspecting JWT payloads, or extracting data URIs.

Need to encode to Base64? Try our Base64 Encoder →

Frequently Asked Questions

Is it safe to decode sensitive data here? Yes. All decoding happens in your browser using JavaScript. No data is transmitted to any server, so your encoded strings remain completely private.

What is the difference between Base64 and URL-safe Base64? Standard Base64 uses + and / characters, which are special characters in URLs. URL-safe Base64 replaces them with - and _ so the string can be used safely in URLs and filenames without percent-encoding.

Why does my decoded output look like gibberish? If the original data was binary (such as an image, PDF, or compressed file), the decoded output will not be readable text. In that case, the Base64 string represents a binary file, not a text string.

Is Base64 a form of encryption? No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string without a key. It should never be used to protect sensitive data — use proper encryption for that.

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