Convert Base32 to Plain Text Decode Base32-encoded strings back to plain text.
Base32 Decode
Decode Base32-encoded strings back to plain text.
Paste Base32
Paste the Base32-encoded string into the input field.
View Decoded Text
The decoded plain text appears instantly.
Copy Result
Click Copy to copy the decoded text.
What Is Base32 Decode?
Base32 decoding reverses the encoding process, converting an encoded string back into its original binary data or text. Each group of 8 encoded characters maps back to 5 bytes. The decoder strips padding characters and handles both uppercase and lowercase input since the encoding is case-insensitive. This tool validates the input against the RFC 4648 Base32 alphabet and reports errors for invalid characters. The decoded bytes are interpreted as UTF-8 text. All processing happens in your browser for maximum privacy.
Why Use Base32 Decode?
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Handles both uppercase and lowercase Base32 input
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RFC 4648 compliant with proper validation
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100% client-side — data never leaves your browser
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Free online tool with clear error messages for invalid input
Common Use Cases
TOTP Debugging
Decode Base32-encoded TOTP secrets to verify their values.
Data Recovery
Decode Base32 data from legacy systems and configurations.
Security Analysis
Inspect Base32-encoded payloads in security research.
Protocol Debugging
Decode Base32 data from DNS, Tor, and other protocols.
Technical Guide
Base32 decoding maps each character to its 5-bit value (A=0 through 7=31), concatenates the bits, and extracts bytes. The decoder normalizes input to uppercase, strips whitespace and padding, validates characters, processes 8-character groups extracting 5 bytes each, and handles the final partial group correctly. Invalid characters produce clear error messages.
Tips & Best Practices
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1Input is case-insensitive — both uppercase and lowercase work
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2Whitespace and padding are automatically stripped
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3Use this to verify TOTP secret keys during 2FA debugging
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4Invalid characters will produce a clear error message
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🔐 Encoding & CryptoFrequently Asked Questions
Q Is this tool free?
Q Is my data secure?
Q Is Base32 decoding case-sensitive?
Q What browsers are supported?
Q What if my input has padding?
About This Tool
Base32 Decode is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.