UNIX Time Converter
Convert UNIX timestamps (seconds or milliseconds) to UTC/local time and back.
The tool auto-detects whether the input is 10-digit seconds or 13-digit milliseconds
and updates all fields in real time with no API calls.
View ISO 8601 output, human-readable strings, and the detected weekday.
Quick actions let you copy any field, jump to the current time, auto-refresh every second, or clear inputs.
All calculations are done in your browser using the native Date and Intl APIs.
Auto-detects seconds or milliseconds
Auto-syncs with UNIX input. Accepts local time.
Unix Timestamp Converter
Unix timestamps appear in logs, databases, API responses, JWT claims, analytics exports, and monitoring alerts. This converter turns second-based or millisecond-based timestamps into readable dates and helps you convert dates back into timestamp values.
Common use cases
- Debug logs: Convert raw timestamps into human-readable times during incident investigation.
- Check API fields: Review
created_at,updated_at,iat,exp, and expiration values. - Validate stored data: Confirm whether database timestamps match expected user actions or system events.
Seconds vs milliseconds
A 10-digit timestamp is often seconds, while a 13-digit timestamp is often milliseconds, but systems vary. If the resulting date looks far in the past or future, check whether you are using the correct unit.
Articles for this tool
Unix Time and Timezones: A Practical Engineering Reference
Master Unix timestamps — what they are, the seconds vs milliseconds trap, timezone handling in JavaScript, Python, Go, and SQL, the 2038 problem, and how to convert them reliably.
How to Convert Milliseconds, Seconds, Minutes, and Hours for Timeouts and TTLs
Convert time units for API timeouts, cache TTLs, retry delays, polling intervals, and monitoring settings without mixing up milliseconds and seconds.
Recent Articles
CREATE TABLE Reference: MySQL vs PostgreSQL vs SQLite Types & Constraints
A cross-database CREATE TABLE (DDL) reference with cheat sheets for data types, auto-increment keys (AUTO_INCREMENT / IDENTITY / rowid), foreign key ON DELETE behavior, and the CHECK constraint that MySQL silently ignores.
How CREATE TABLE Generation From a Visual Table Design Works | DDL Builder
A look inside DDL Builder, which turns a visually designed table into CREATE TABLE statements and an ER diagram. Covers the MySQL/PostgreSQL/SQLite type-mapping rules and the column-inference algorithm used for JSON samples.
GitHub Actions needs Design Patterns: Speed Up CI, Avoid the Anti-Patterns
A pattern reference for GitHub Actions job dependencies (needs). Covers diamond-shaped fan-out, concurrency cancellation, fail-fast tradeoffs, matrix-plus-needs gotchas, and reusable workflows, with copy-paste YAML examples.
SQL JOIN Types: Complete Reference to INNER, LEFT, RIGHT & FULL
A reference for SQL JOIN types (INNER/LEFT/RIGHT/FULL/CROSS/SELF) with a cheat sheet and row-count walkthroughs. Covers why one-to-many joins duplicate rows, the WHERE-vs-ON NULL trap, and how to write multi-table joins.
Case Converter: camelCase, snake_case & kebab-case — 9 Styles at Once
Convert identifiers between camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case and more — all nine styles side by side. Handles acronym runs like HTTPServer, digits, and bulk multi-line conversion.
LLM API Cost Calculator: Compare Claude, GPT & Gemini Pricing Side by Side
Paste a prompt, set the expected output tokens, and compare per-request API costs across Claude, GPT and Gemini models. Covers input/output pricing structure, auto-updated price tables, and estimate limits.