Decode Base64 to text through nested Base64/Base64URL, GZIP, zlib, UTF-8, and UTF-16 layers, or encode text locally.
Enter text and choose an action.
Decode ordinary Base64, Base64URL, nested Base64, and common Base64-wrapped compressed text such as GZIP or zlib. The auto decoder keeps unwrapping supported layers until readable UTF-8 or UTF-16 text is reached, then shows the exact chain it detected. Base64 is encoding, not encryption.
The browser strictly decodes Base64/Base64URL, checks binary signatures, safely decompresses detected GZIP or zlib layers, detects UTF-8/UTF-16 text, and repeats when the resulting text is itself Base64. Processing remains in this tab with explicit layer and decoded-size limits.
| Property | Behavior |
|---|---|
| Processing | Browser local; input and decoded text stay in this tab |
| Auto layers | Base64, Base64URL, GZIP, zlib, UTF-8, UTF-16LE/BE |
| Recursion | Up to 32 supported transformations |
| Decoded payload | 32 MiB safety ceiling |
| Encryption | Not decrypted; requires the actual algorithm/key |
A normal Base64 decoder performs one representation change. That is not enough when an application first compresses text with GZIP or zlib and then Base64-encodes the compressed bytes, or when Base64 has been applied more than once. Auto decode follows supported layers one at a time and displays the detected chain.
Recursive decoding cannot safely promise to understand every possible byte stream. Encrypted content, proprietary formats, arbitrary binary files, and raw DEFLATE without a trustworthy signature require format-specific knowledge. OpenFileTools stops instead of presenting replacement characters as if they were valid decoded text.
Manual Base64 and Base64URL encode/decode remain available. This is useful when debugging a protocol where you need to inspect one layer at a time rather than accept automatic recursion. The GZIP + Base64 encoder can also create the common compressed-text representation for round-trip testing.
Because the Base64 payload commonly contains GZIP-compressed bytes. The next required operation is GZIP decompression, followed by text decoding.
Yes, for supported and plausible layers. It stops at readable non-Base64 text, unknown binary, an unsupported format, or the recursion/size safety boundary.
Not without the correct cryptographic algorithm and key. Base64 only changes the representation of the encrypted bytes.