Tools for Sysadmins
System administrators live at the command line, but sometimes a fast browser tool is the right choice: validate a cron schedule, decode a Base64 secret, look up an IP address, or build a cURL command for a runbook. Here are the Tools.Fun utilities sysadmins use most — all free, client-side, no account required.
Crontab Calculator
Paste any cron expression and get a plain-English explanation plus the next 10 run times. Prevents the "it ran at 3 AM instead of 3 PM" incident. Supports standard 5-field cron syntax and common shorthand like @daily and @reboot.
IP Lookup
Geolocate any IPv4 or IPv6 address instantly: country, city, ASN, hosting provider, and organization. Use it when triaging incidents, reviewing access logs, or investigating suspicious traffic sources.
cURL Converter
Convert cURL commands into readable request breakdowns — or build a cURL command from scratch. Write once, paste into runbooks, share with teammates who are less comfortable with raw cURL syntax, and use in post-mortems.
User-Agent Parser
Paste any User-Agent string and get a structured breakdown: browser engine, OS, device type, and exact version numbers. Useful for analysing web server access logs and debugging compatibility issues across client types.
WebSocket Tester
Connect to any WebSocket endpoint and send / receive frames directly in the browser. Test push notification services, log streamers, and real-time monitoring feeds without installing a CLI client.
Password Generator
Generate cryptographically strong random passwords with full control over length, character classes, and entropy. Use when provisioning new service accounts, rotating shared credentials, or generating API keys and tokens.
MD5 / Hash Generator
Compute MD5, SHA-1, SHA-256, and SHA-512 hashes to verify file integrity, compare downloaded package checksums, or quickly generate expected hash values — without a one-liner script every time.
Base64 Encoder / Decoder
Decode Base64 values from Kubernetes secrets, Docker config JSON, SSH authorized keys stored in YAML, and CI environment variables. Encode raw values for embedding in manifests or config files.
JSON Formatter
Pretty-print and validate JSON blobs from API responses, log aggregators, and health check endpoints. Makes dense payloads readable in seconds when you need to find the exact field during an incident.
JSON to YAML Converter
Convert JSON configs to YAML for Kubernetes manifests, Helm charts, Ansible playbooks, and GitHub Actions workflows. No manual reformatting required.
Timestamp Converter
Convert Unix timestamps to human-readable dates while reading logs in Kibana, CloudWatch, Loki, or raw log files. Generate epoch values for time-range queries without mental arithmetic.
Code Diff Tool
Compare two versions of a config file, Nginx vhost, firewall rule set, or shell script side by side. Faster than diff on the command line when you're working in a browser-based runbook.
RegExp Tester
Test log-parsing patterns and input filters in real time. Essential for building grep / awk patterns, writing fail2ban rules, and constructing log aggregation filter expressions.
AES Encryptor
Encrypt and decrypt configuration values and secrets using AES-256 for quick testing of symmetric encryption in your applications without writing a script.
RSA Encryptor
Test RSA key pairs and verify that public/private key operations produce the expected output. Useful when debugging PKI-related issues in TLS certificates and token signing.
DES Encryptor
Work with legacy DES-encrypted payloads when integrating with older enterprise systems that haven't migrated to AES.
Hex Converter
Convert between hexadecimal, decimal, and binary. Handy when reading raw network packet captures, MAC addresses, and memory addresses in kernel or device logs.
URL Encoder / Decoder
Decode percent-encoded URLs from web server logs or encode special characters for use in API calls, webhook payloads, and connection strings.
Duplicate Line Counter
Paste a list of IPs, hostnames, or log entries and instantly remove duplicates. Faster than sort | uniq when you're working in a browser environment.
Distance Calculator
Calculate the geographic distance between two IP-based locations or coordinates — useful for capacity planning, CDN edge placement analysis, and latency estimation.
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