Parse ULID timestamp and randomness
Quick CTA
Paste one ULID per line and inspect timestamps plus validity first; random-segment details stay in Deep.
Next step workflow
Deep expands pitfalls, recipes, snippets, FAQ, and related tools when you need troubleshooting or deeper follow-through.
ULID Parser decodes ULID strings into human-readable timestamp and randomness details. It validates the 26-character Crockford Base32 format, extracts creation time, and presents the random portion in hex for easier inspection. This is useful when analyzing event timelines, verifying ID generation behavior, and debugging distributed systems that rely on lexicographically sortable IDs. Batch input is supported so you can parse multiple IDs at once and compare generation windows quickly. Processing is entirely local in your browser for fast and privacy-safe troubleshooting.
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01ARZ3NDEKTSV4RRFFQ69G5FAVBad input: Combining upper and lower case ULIDs in one import job and assuming all clients normalize automatically.
Failure: Cross-service equality checks fail and duplicate records appear in sync jobs.
Fix: Normalize case before storage and validate allowed charset/length at ingest time.
Bad input: Using ULID time part as the final event timestamp for SLA and billing reports.
Failure: Backfilled or delayed writes are mis-attributed, skewing analytics windows.
Fix: Keep ULID timestamp for ordering diagnostics only; report with explicit domain event time.
Bad input: ULIDs from different nodes are sorted without clock health checks.
Failure: Incident timeline appears to contradict real processing order.
Fix: Combine ULID parsing with node clock-offset diagnostics.
Bad input: Non-ULID strings are mixed into the input list.
Failure: Output looks valid but downstream systems reject or misread it.
Fix: Normalize input format and add a preflight validation step before export.
Bad input: Parsed timestamps are interpreted in the wrong timezone.
Failure: Different environments produce inconsistent results from the same source data.
Fix: Document compatibility mode and verify with at least one independent consumer.
Parser
Use it when you already have IDs and need to inspect or decode them.
Generator
Use it when you need to mint new sortable unique IDs.
Note: Generate when creating IDs, parse when explaining IDs that already exist in the wild.
ULID embedded time
Use for quick ordering diagnostics and rough sequencing.
Domain event timestamp
Use for SLA, billing, and compliance reports.
Note: ULID time is useful for triage, not a full business-time substitute.
Quick output
Use for one-off internal checks with low blast radius.
Validated workflow
Use for production pipelines, audits, or customer-facing output.
Note: ULID parser should be treated as a workflow step, not an isolated click.
Single pass
Use when turnaround time is more important than traceability.
Stage + verify
Use when reproducibility and post-incident replay are required.
Note: A staged path usually prevents silent data-quality regressions.
Recommend: Use ULID parsing to extract order hints while retaining source event timestamps.
Avoid: Avoid assuming ULID monotonicity across independent generators without coordination.
Recommend: Prefer opaque random IDs or hashed surrogates for external exposure.
Avoid: Avoid exposing raw time-encoded IDs when creation-time inference is a risk.
Recommend: Parse timestamp plus node clock context before final timeline claims.
Avoid: Avoid treating ULID ordering as absolute truth across skewed hosts.
Recommend: Use quick mode with lightweight validation.
Avoid: Avoid treating ad-hoc output as production truth.
Recommend: Use staged workflow with explicit verification records.
Avoid: Avoid single-pass output without replayable validation logs.
Q01
Yes. The leading portion encodes timestamp information, which makes ULIDs useful for sorting and trace review.
Q02
The parser can normalize mixed case, but invalid characters or wrong length still make the ULID unusable.
Cause: Wrong characters can still sneak into IDs that look close to valid at a glance.
Fix: Validate charset and structure, not just length.
Cause: The random suffix is useful for uniqueness but does not carry human business meaning by itself.
Fix: Use the timestamp for sequencing and the suffix mostly for uniqueness checks.
Goal: Extract timestamp and random segments from ULIDs during debugging or trace reconstruction.
Result: You can turn opaque ULIDs into something more actionable during incident review.
Goal: Use parsed ULID time as a hint while preserving true domain event timestamps.
Result: Incident reviews separate generation-order issues from business-time issues.
Goal: Extract timestamp ordering clues during incident analysis.
Result: Event ordering analysis becomes more reliable.
Goal: Reduce avoidable rework by validating assumptions before publishing output.
Result: Teams can ship faster with fewer back-and-forth fixes.
Goal: Turn production anomalies into repeatable diagnostic steps.
Result: Recovery time decreases because operators follow a tested path.
ULID Parser is most reliable with real inputs and scenario-driven decisions, especially around "Distributed logs and append-only feeds needing sortable IDs".
It outputs validity, millisecond timestamp, ISO datetime, and random segment in hex format.
You can verify ordering, inspect generation windows, and compare IDs from different services quickly.
A 26-character Crockford Base32 ULID using digits and uppercase letters without I, L, O, U.
Yes. Paste one ULID per line and the tool will parse each row independently.
No. Invalid rows are marked so you can correct source data explicitly.
Yes. No input is sent to a backend.