ULID Decoder
Decode ULID timestamps, inspect the 48-bit time and 80-bit tail, and review batch errors locally. Copy exact Unix milliseconds or download a complete JSON report.
Enabling local controls…
Paste ULIDs
26 Crockford Base32 characters; ASCII case is normalized. Only outer ASCII spaces / tabs are trimmed. Up to 1,000 non-blank lines · 128 KiB UTF-8.
Processed in this page's memory. Identifiers are not uploaded, saved or added to the URL. Prefer non-sensitive samples; identifiers can link private records.
Inspect the encoded fields
Load a synthetic example to see an exact UTC timestamp, its 80-bit tail and all 16 bytes.
The timestamp is 48 bits; the tail is 80 bits. Decoding is not identity or security verification.
Review and export
The complete JSON report includes all original identifiers, decoded values and error rows. Review it before sharing; downloading is not anonymization.
How to use this tool
Paste one 26-character ULID per line or load a synthetic example. Select a row to inspect its UTC time, bytes and bit fields, then review every original row before copying or downloading the report.
When not to use it
Encoded time is not proof of record creation, identity, uniqueness or secure randomness. ULIDs can link private records; decoding is not authentication or anonymization.
Read the guide →