Programmatic Utility Hub for
Sysadmins & DevOps
Zero-latency calculators, container manifest generators, and protocol analyzers. No frameworks, zero tracking, and instant offline computation.
Most Used Utilities Community Favorites
Most launched tools automatically ordered by real-time usage.
CIDR & VLSM Visual Calculator
Interactive IPv4 CIDR subnet visualizer, usable IP range calculator, dotted decimal netmask, wildcard mask, and binary address decomposition.
Docker Compose Template Generator
Generate production-ready docker-compose.yml manifests for self-hosted apps with persistent volumes, restart policies, and port bindings.
Port Conflict & Protocol Directory
Fast directory and conflict inspector for standard TCP/UDP service ports with security advisories and firewall rule blueprints.
Nginx Reverse Proxy & SSL Block Generator
Generate secure, modern Nginx server configurations with reverse proxy headers, WebSocket support, Let's Encrypt SSL directives, and hardening headers.
Linux Permissions CHMOD Calculator
Visual octal and symbolic Linux file permission calculator with SUID, SGID, sticky bit, and command line generator.
Homelab UPS & Battery Backup Runtime Estimator
Estimate runtime under continuous wattage load for 12V/24V/48V battery systems, accounting for inverter efficiency, depth of discharge, and C-ratings.
What do you want to accomplish today?
Pick a common sysadmin task below for interactive calculators with zero confusing jargon.
Divide an IP Network or Subnet
No subnet math required. Enter your IP and slide the CIDR bar from /8 to /32 to see usable hosts and masks.
Deploy Apps with Docker Compose
Choose Nextcloud, Plex, AdGuard, or WireGuard. Get clean, copy-paste ready YAML files in 1 click.
Check Port Services & Firewall Rules
Resolve port conflicts. Find out which software uses port 22, 443, 8080, or 9000 and view security specs.
Fix "Permission Denied" Errors
Toggle Read, Write, and Execute checkboxes to calculate numeric chmod values (755, 644, 777) instantly.
Estimate UPS Battery Backup Runtime
Enter your server watt load and battery amp-hours to see exact minutes and hours of backup power.
Generate Nginx Reverse Proxy Configs
Connect your custom domain to any internal port or Docker container with automatic security headers.
Interactive Utility Library
Select a category or browse all high-impact utilities.
CIDR & VLSM Visual Calculator
Interactive IPv4 CIDR subnet visualizer, usable IP range calculator, dotted decimal netmask, wildcard mask, and binary address decomposition.
Port Conflict & Protocol Directory
Fast directory and conflict inspector for standard TCP/UDP service ports with security advisories and firewall rule blueprints.
Network Bandwidth Transfer Time Calculator
Compute download, upload, and backup transmission times across varying connection speeds, link latency, and transfer protocol overheads.
IPv6 Address Expander & Compressor
Expand shortened IPv6 addresses into full 8-hextet 128-bit format and compress standard IPv6 notation conforming strictly to RFC 5952.
MAC Address Vendor OUI Lookup & Formatter
Identify network interface card manufacturers from IEEE Organizationally Unique Identifiers (OUI) and reformat MAC delimiter notation.
DNS Zone Record & SPF / DMARC Generator
Build compliant SPF TXT records, DMARC policy tags, MX preferences, CNAME mappings, and CAA certificate authority authorizations.
MTU, MSS & VPN Overhead Calculator
Compute Maximum Segment Size (MSS) and maximum transmission unit allowances for WireGuard, IPsec ESP, OpenVPN, VXLAN, and PPPoE tunnels.
IP Range to CIDR Block Aggregator
Convert arbitrary start-to-end IPv4 IP address spans into the minimal set of optimized CIDR prefixes with zero waste.
Docker Compose Template Generator
Generate production-ready docker-compose.yml manifests for self-hosted apps with persistent volumes, restart policies, and port bindings.
Nginx Reverse Proxy & SSL Block Generator
Generate secure, modern Nginx server configurations with reverse proxy headers, WebSocket support, Let's Encrypt SSL directives, and hardening headers.
Visual Crontab Syntax Generator & Humanizer
Translate complex 5-part cron syntax into plain English explanations and visually construct automated scheduling directives.
Systemd Unit File (.service) Generator
Generate production-grade Linux systemd service unit files with watchdog supervision, custom user isolation, environment files, and restart rules.
Multi-Stage Dockerfile Blueprint Builder
Create optimized, minimal, rootless container Dockerfiles for Node.js, Python, Go, PHP, and Rust with security and caching best practices.
Apache & Nginx .htpasswd Bcrypt Generator
Generate secure HTTP Basic Authentication credentials using salted Bcrypt and APR1 hashing for Nginx, Apache, and Traefik ingress.
OpenSSH Client Config (~/.ssh/config) Builder
Assemble clean OpenSSH client configs with host aliases, identity files, ProxyJump bastion chains, and TCP keep-alive options.
Traefik v3 Dynamic Docker Label Generator
Quickly construct Traefik reverse proxy container labels for automatic Let's Encrypt TLS challenge, middleware routers, and host routing.
Kubernetes Manifest YAML Generator
Scaffold production Kubernetes Deployment, ClusterIP / NodePort Service, and Ingress YAML resources with resource limits and probes.
Linux Permissions CHMOD Calculator
Visual octal and symbolic Linux file permission calculator with SUID, SGID, sticky bit, and command line generator.
Cryptographic Password & Secret Token Generator
Generate high-entropy randomized sysadmin passwords, API bearer tokens, and hex secrets using window.crypto CSPRNG.
Multi-Algorithm Hash & Checksum Calculator
Calculate cryptographic SHA-256, SHA-512, SHA-1, and MD5 message digests instantly in-browser without uploading data.
OpenSSL CSR & Private Key Command Generator
Generate OpenSSL CLI commands to generate Certificate Signing Requests (CSR) with Subject Alternative Names (SAN) and 4096-bit RSA/ECC keys.
Base64, Hex & URL String Encoder / Decoder
Encode and decode strings across Base64, Hexadecimal, and URL encoding formats with byte length counting and UTF-8 support.
WireGuard Keypair & Peer Config Generator
Generate WireGuard public/private key pairs and ready-to-use wg0.conf server and client configuration manifests.
UUID v4 & ULID Batch Generator
Generate cryptographically random UUID version 4 and lexicographically sortable ULIDs in batches with one-click export.
HTTP CORS & Security Header Generator
Construct Content-Security-Policy (CSP), CORS access headers, and HSTS directives for web servers and API gateways.
Homelab UPS & Battery Backup Runtime Estimator
Estimate runtime under continuous wattage load for 12V/24V/48V battery systems, accounting for inverter efficiency, depth of discharge, and C-ratings.
DC 12V/24V Wire Gauge (AWG) Voltage Drop Calculator
Determine optimal wire thickness (AWG/mm²), voltage drop percentage, and conductor resistance for low-voltage homelab and IoT electrical installations.
RAID Storage Capacity & Parity Calculator
Calculate usable disk capacity, fault tolerance, and parity storage efficiency across RAID 0, 1, 5, 6, 10, and ZFS RAID-Z1/Z2 arrays.
Homelab Server Electricity Cost Calculator
Estimate monthly and annual running costs for servers, NAS boxes, and switches based on wattage draw and US/UK regional electricity tariffs.
PoE Power Budget (802.3af / at / bt) Allocator
Calculate Power over Ethernet switch power budget headroom across Type 1 (15.4W), Type 2 PoE+ (30W), and Type 4 PoE++ (90W) devices.
Server Rack Thermal Heat (BTU/hr & CFM) Calculator
Convert homelab kilowatt draw into heat dissipation in BTU/hr and estimate required cubic feet per minute (CFM) server rack cooling airflow.
Storage IOPS & MB/s Throughput Calculator
Estimate theoretical and real-world IOPS and queue-depth performance across mechanical SAS/SATA HDDs, SATA SSDs, and NVMe drives.
Unix Epoch Timestamp Converter & Formatter
Convert Unix seconds, milliseconds, and microseconds timestamps to UTC and local human-readable ISO 8601 date strings.
High Availability SLA Uptime / Downtime Calculator
Calculate allowed downtime per day, week, month, and year for 99.9%, 99.95%, 99.99%, and "Five Nines" (99.999%) SLA commitments.
cURL Command Builder & REST API Tester
Visually assemble cURL commands with HTTP methods, custom headers, bearer authentication, form data, and JSON request payloads.
Sysadmin Log Regex Tester & Pattern Library
Test JavaScript regex patterns against server log files with instant match highlighting and presets for IPs, timestamps, and HTTP status codes.
Linux dd & fio Benchmark Command Generator
Generate safe disk read/write throughput benchmark commands using dd (direct I/O) and fio for server storage validation.
URL Query String & URI Component Inspector
Parse complex URLs into protocol, host, port, path, and decode query string key-value pairs into structured parameters.
HTTP User-Agent Parser & Bot Detector
Analyze client User-Agent strings to identify browser engines, operating systems, mobile devices, and automated search engine crawlers.
# Standard Port Directory & Security Specs
Instant protocol specifications, firewall blueprints, and risk profiles for common TCP/UDP ports.
| Port | Protocol | Service Name | Firewall Spec |
|---|---|---|---|
| 20 | TCP | FTP-Data | ufw / iptables |
| 21 | TCP | FTP-Control | ufw / iptables |
| 22 | TCP | SSH / SFTP | ufw / iptables |
| 23 | TCP | Telnet | ufw / iptables |
| 25 | TCP | SMTP | ufw / iptables |
| 53 | TCP/UDP | DNS | ufw / iptables |
| 67 | UDP | DHCP Server | ufw / iptables |
| 68 | UDP | DHCP Client | ufw / iptables |
| 69 | UDP | TFTP | ufw / iptables |
| 80 | TCP | HTTP | ufw / iptables |
| 110 | TCP | POP3 | ufw / iptables |
| 123 | UDP | NTP | ufw / iptables |
| 143 | TCP | IMAP | ufw / iptables |
| 161 | UDP | SNMP | ufw / iptables |
| 389 | TCP/UDP | LDAP | ufw / iptables |
| 443 | TCP/UDP | HTTPS / QUIC | ufw / iptables |
| 445 | TCP | SMB / CIFS | ufw / iptables |
| 587 | TCP | SMTP Submission | ufw / iptables |
| 636 | TCP | LDAPS | ufw / iptables |
| 993 | TCP | IMAPS | ufw / iptables |
Featured Architecture Guides
In-depth technical writeups on system architecture, power, and security.
The Complete Sysadmin Guide to IPv4 Subnetting & VLSM
Master IPv4 subnet division, wildcard masks, point-to-point /31 prefixes, and Variable Length Subnet Masking with real-world network engineering formulas.
How to Size a Homelab UPS: Chemistry & Runtime Formulas
Learn how to accurately size battery backup supplies for rack servers, factoring in inverter conversion efficiency and high C-rate Peukert penalties.
Production Docker Compose Hardening: 10 Security Patterns
A practical checklist for securing self-hosted Docker stacks: rootless execution, read-only root filesystems, and avoiding socket exposure.