Why does decoding fail?

Wrong alphabet, corrupt Base64, data that is not gzip-wrapped, or UTF-8 that fails strict decoding.

Standard Base64 is expected; normalize URL-safe forms elsewhere if needed.

Use the regular Base64 decode tool; gzip decode expects compressed binary inside the Base64.

Data sent to a server?

No. Decompression runs locally.

Base64 Gzip Decode Online – Decode & Decompress Instantly

Decode Base64 gzip data instantly with this free online tool. Paste your compressed Base64 string to decode and decompress it into readable text — perfect for inspecting API responses and logs.

Base64 Gzip Input

Text

Related tools

How it works

Whitespace is stripped from the Base64 input, bytes are decoded, then the gzip stream is decompressed.

The result is interpreted as UTF-8 text with strict validation.

Use cases

Unpack payloads from APIs, logs, or the matching encoder on this site.

Not encryption

Anyone with the Base64 string can recover the original. Treat decoded text like any sensitive content.

Common questions

Why does decoding fail?: Wrong alphabet, corrupt Base64, data that is not gzip-wrapped, or UTF-8 that fails strict decoding.
URL-safe Base64?: Standard Base64 is expected; normalize URL-safe forms elsewhere if needed.
Plain Base64 text?: Use the regular Base64 decode tool; gzip decode expects compressed binary inside the Base64.
Data sent to a server?: No. Decompression runs locally.