Cron Expression Validator — Schedule Checker
Validate cron expressions, get a plain-English explanation of what they mean, and see the next scheduled run times — all in your browser.
How to Use Cron Expression Validator — Schedule Checker
How to Use the Cron Expression Validator
Step 1: Enter a Cron Expression
Type or paste a standard 5-field cron expression into the input:
minute hour day-of-month month day-of-week
For example:
* * * * *— every minute0 9 * * MON-FRI— 9:00 AM on weekdays*/15 * * * *— every 15 minutes@daily— once a day at midnight
Step 2: Read the Plain-English Explanation
The validator immediately shows what your expression means in plain English — no cron knowledge required.
Step 3: Review the Field Breakdown
Each of the 5 fields is explained individually:
| Field | Range | Accepted Values |
|---|---|---|
| Minute | 0–59 | Numbers, *, */n, ranges, lists |
| Hour | 0–23 | Numbers, *, */n, ranges, lists |
| Day of month | 1–31 | Numbers, *, */n, ranges, lists |
| Month | 1–12 | Numbers or JAN–DEC, *, ranges |
| Day of week | 0–7 | Numbers (0=Sun, 7=Sun) or SUN–SAT |
Step 4: See the Next Scheduled Runs
For valid expressions, the tool shows the next 5 upcoming execution times computed from now.
Special Aliases
The tool supports the following shorthand aliases:
| Alias | Equivalent |
|---|---|
| @yearly | 0 0 1 1 * |
| @annually | 0 0 1 1 * |
| @monthly | 0 0 1 * * |
| @weekly | 0 0 * * 0 |
| @daily | 0 0 * * * |
| @midnight | 0 0 * * * |
| @hourly | 0 * * * * |
Tips
- Click an example pill to load a common expression instantly
- Named months and weekdays are case-insensitive (e.g.,
Mon,MON,mon) 7is accepted as an alias for Sunday in the day-of-week field- All validation happens locally — your expressions are never sent anywhere
Frequently Asked Questions
Most Viewed Tools
Screen Size Converter — Diagonal Dimension Tool
Calculate screen width and height from diagonal size and aspect ratio. Convert between inches and centimeters for displays, TVs, and monitors with instant dimension calculations.
Use Tool →TOTP Code Generator — 2FA Testing Tool
Generate time-based one-time passwords from a TOTP secret key. Enter your base32 secret, choose a period and digit length, and get the current and next codes with a live countdown timer. Useful for testing and debugging 2FA integrations.
Use Tool →JSON to Zod — Schema Generator
Generate Zod validation schema code from a JSON sample object. Infers z.string(), z.number(), z.boolean(), z.array(), z.object(), and z.null() types automatically. Handles nested objects, arrays of objects with optional field detection, and outputs copy-ready TypeScript with import and z.infer type alias.
Use Tool →JSONL Formatter — Line-by-Line Validator
Format, validate, and inspect JSON Lines (JSONL) and NDJSON files. Validates each line individually, reports parse errors by line number, outputs compact JSONL or a pretty-print preview, and lets you download the cleaned file.
Use Tool →TLS Cipher Suite Checker — Strength Analyzer
Check TLS protocol version compatibility and cipher suite strength ratings against current best practices. Supports IANA and OpenSSL cipher names — rates each suite as Strong, Weak, or Deprecated and explains why.
Use Tool →Password Entropy Calculator — Crack Time Estimator
Calculate the information-theoretic bit entropy of any password or API key. Detects character set pools automatically, shows the total number of possible combinations, and estimates crack time across five attack scenarios from rate-limited web logins to GPU cracking clusters.
Use Tool →DPI Calculator — Print Resolution Tool
Calculate DPI (dots per inch), image dimensions, and print sizes. Convert between pixels and physical dimensions for printing and displays.
Use Tool →Secret Scanner — API Key & Credential Detector
Scan pasted text, code, or config files for accidentally exposed API keys, tokens, passwords, and private keys. Detects 50+ secret types across AWS, GitHub, Stripe, OpenAI, and more — all client-side, nothing leaves your browser.
Use Tool →Related DevOps & Infrastructure Tools
Kubernetes YAML Validator — K8s Manifest Schema & Security Audit
Validate Kubernetes YAML manifests for syntax errors and required field completeness. Checks Deployments, Services, Ingress, ConfigMaps, Secrets, PVCs, HPAs, CronJobs, and more — with per-document results and fix hints.
Use Tool →Dockerfile Linter — Optimize & Secure Your Container Builds
Lint Dockerfile instructions for best practices, security issues, and layer optimization. Flags unpinned base images, root user, ADD vs COPY, apt-get mistakes, shell-form CMD, and more — with fix guidance for each issue.
Use Tool →Port Number Lookup — Common TCP/UDP Service & Protocol Database
Searchable reference for 80+ well-known TCP and UDP ports. Look up any port number or service name to see the official protocol, service description, port range (well-known/registered), and security recommendations for risky ports.
Use Tool →Cookie Parser — HTTP Cookie Decoder
Parse HTTP cookie strings into readable key-value pairs. Decode URL-encoded values and inspect cookies from browser requests.
Use Tool →CIDR Calculator — IPv4 Subnet & Network Range Mapper
Calculate subnet ranges, usable host counts, broadcast addresses, and subnet masks from CIDR notation. Shows network and host addresses in both decimal and binary with color-coded bit visualization.
Use Tool →Docker Compose Validator — Multi-Container YAML Syntax & Logic Check
Validate docker-compose.yml syntax, service definitions, networks, volumes, and environment variables. Catches YAML errors, broken depends_on references, missing image/build, invalid restart policies, and more — with context-aware hints.
Use Tool →HTTP Header Analyzer — Security & CORS Audit
Parse and analyze HTTP request or response headers. Identifies categories, explains each header, flags missing security headers, and detects duplicates or suspicious values — entirely in your browser.
Use Tool →SSL Certificate Decoder — Expiry & SAN Inspector
Decode X.509 SSL/TLS certificates and RSA private keys in your browser. View subject, issuer, SANs, validity dates, key type, serial number, and SHA-256/SHA-1 fingerprints. Optionally check if a certificate and private key match.
Use Tool →Share Your Feedback
Help us improve this tool by sharing your experience