Base64 Decoder - Decode Base64 to Text Online
Decode Base64 encoded strings back to plain text quickly and easily with our free online Base64 decoder tool. Supports standard and URL-safe Base64 decoding.
Base64 Decoder
Decode Base64 encoded text back to plain text. Supports file upload and download.
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What is Base64 Decoding?
Base64 decoding is the reverse process of Base64 encoding. It converts Base64-encoded ASCII strings back into their original binary or text format. The decoder reads 4 Base64 characters (24 bits) and converts them back into 3 bytes of original data.
Base64 decoding is essential when you receive encoded data and need to restore it to its original, readable form.
Why use Base64 Decoding?
- Data Retrieval: Convert Base64-encoded data back to its original format
- API Response Processing: Decode Base64 strings from API responses
- Reading Encoded Files: Extract original content from Base64-encoded files
- Token Inspection: Decode JWT tokens or authentication credentials
- Debugging: Inspect Base64-encoded data during development
Base64 Decoding Examples
Base64:
SGVsbG8sIFdvcmxkIQ==Decoded Text:
Hello, World!Base64:
eyJuYW1lIjoiSm9obiIsImFnZSI6MzB9Decoded Text:
{"name":"John","age":30}URL-Safe Base64:
SGVsbG8tV29ybGQhDecoded Text:
Hello-World!Common Mistakes
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Using Wrong Decoder Type: Standard vs URL-safe Base64 use different characters. Make sure to select the correct mode.
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Including Extra Whitespace: Line breaks or spaces in Base64 strings can cause decoding errors. Remove them first.
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Corrupted Base64 String: Invalid characters or truncated strings will fail to decode. Ensure the complete encoded string is used.
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Character Set Issues: The decoded output’s character encoding (UTF-8, ASCII) must match the original encoding.
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Expecting Readable Output: Not all Base64 data decodes to readable text—it might be binary data like images or files.
FAQs
Q: Can I decode any Base64 string?
A: Yes, but the output might be binary data rather than readable text. Text-based data will decode to readable characters.
Q: What happens if the Base64 string is invalid?
A: The decoder will show an error message. Check for typos, missing characters, or incorrect padding.
Q: How do I know if it’s URL-safe Base64?
A: URL-safe Base64 uses - and _ instead of + and /, and typically omits padding (=).
Q: Is my decoded data secure?
A: Base64 is not encryption—anyone can decode it. Don’t rely on Base64 for security or privacy.
Q: Can I decode binary data like images?
A: Yes, but the output will be binary data. For images, you’d need to save the decoded bytes as an image file.
Q: Why do I see strange characters after decoding?
A: The original data might be binary, or there’s a character encoding mismatch. Ensure the encoding matches the original.