Decode Base64-encoded text to readable strings instantly.
Decoded Text
Hello, World!
Base64 is a binary-to-text encoding scheme that converts binary data into a sequence of printable ASCII characters. Paste a valid Base64 string to decode it.
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What is the Base64 Decoder?
Base64 is a binary-to-text encoding scheme that represents binary data using only 64 safe ASCII characters (A-Z, a-z, 0-9, +, /). A Base64 decoder reverses this process, taking the scrambled Base64 string and restoring it to its original form—whether that's plain text, JSON, XML, or other data. It's used when data must be transmitted safely across systems that only support text, such as email attachments or API responses.
How it works
The decoder takes your Base64-encoded input and converts each character back to its 6-bit binary representation, then groups those bits into 8-bit bytes and converts them to ASCII characters. Modern decoders autodetect the encoding (UTF-8, Latin-1, etc.) and handle common variations like padding characters (=) and line breaks. The process is instantaneous and lossless—the output is identical to the original input before encoding.
Examples
Input
Result
Notes
SGVsbG8gV29ybGQ=
Hello World
Common greeting decoded from Base64; the trailing = is a padding character indicating 1 byte was added during encoding
eyJuYW1lIjoiSm9obiIsImFnZSI6MzB9
{"name":"John","age":30}
JSON object embedded in Base64; frequently used in JWT tokens and API responses
cHJpY2U9NDkuOTkg
price=49.99
Query parameter encoded; commonly seen in email links and webhook payloads
How to use the Base64 Decoder
Copy or paste your Base64-encoded string into the input field
The decoder automatically processes it and displays the original text in real time
Click the copy button to save the decoded output to your clipboard
If decoding fails or shows garbled text, verify the input is valid Base64 (no spaces or line breaks unless the decoder handles them)
For large encoded data, paste it all at once; the tool handles multi-line input
Check the character count and encoding format shown below the output
Benefits
Instantly inspect API responses and webhook data without external tools or command-line knowledge
Decode JWT tokens to verify claims and debug authentication issues
Read embedded JSON and XML without manual character-by-character decoding
Free and browser-based—no software installation, no data uploaded to servers
Speed up debugging by seeing the actual data hidden in encoded form
Support for multiple character encodings (UTF-8, Latin-1, etc.) in one tool
Tips & common mistakes
Common mistakes
Forgetting to include padding characters (=) at the end—Base64 strings often end with 1 or 2 equals signs, and removing them breaks decoding
Pasting encoded data with line breaks or extra whitespace; always clean the input first
Assuming non-ASCII characters will decode correctly—if the source encoding was not UTF-8, the output may appear garbled
Trying to decode strings that are not actually Base64 (they must use only A-Z, a-z, 0-9, +, /, and = for padding)
Tips
Use this tool to verify JWT tokens (split by dots, decode the middle section to see the payload)
If you receive Base64 in an email or API docs, paste it here to quickly see what it contains before integrating it
For debugging webhooks, encode a test message with our Base64 encoder, then decode it here to confirm round-trip accuracy
Base64 encoded strings are typically 33% larger than the original text, so expect longer output if the original was binary data
Frequently asked questions
Is Base64 encryption?
No. Base64 is encoding, not encryption—it's reversible and offers no security. Anyone can decode a Base64 string. If you need to protect data, use proper encryption algorithms like AES.
Why do APIs use Base64?
APIs use Base64 to safely transmit binary data (images, files, certificates) over text-only channels like HTTP. It ensures special characters don't break the transmission.
Can I decode Base64 images or files?
This tool decodes to text. For binary files and images, use a dedicated Base64 image decoder or save the decoded bytes to a file with the correct extension (e.g., .png, .pdf).
What if my Base64 string has line breaks?
Most modern decoders ignore line breaks. This tool strips them automatically, so paste multi-line Base64 data as-is—it will still decode correctly.
How long can the input be?
Browser-based decoders can typically handle kilobytes to a few megabytes. For very large files, consider command-line tools like `base64 -d` (Linux/Mac) or `certutil -decode` (Windows).
What's the difference between Base64 and Base32 or Base16?
Base64 uses 64 characters and is the most compact; Base32 uses 32 and is case-insensitive; Base16 (hex) uses 16 and is bulkier but human-readable. Each suits different use cases.