Calculate CIDR networks, masks, broadcasts and host ranges
Network Ops Collection
Network & DevOps Tools Hub
IP, CIDR, MAC, ports, User-Agent, URL and HTTP status utilities for everyday diagnostics.
A practical network toolkit for sysadmins, backend engineers, QA and DevOps teams. Calculate IPv4 subnets, expand IP ranges, convert IPv4 formats, generate IPv6 ULA addresses, create or look up MAC addresses, generate random ports, parse User-Agent strings, inspect URLs and reference HTTP status codes.
12Curated tools
3Workflows
3FAQ answers
Built for these intents
Expand IP ranges into address lists
Generate MAC addresses or look up OUI vendors
Parse browser User-Agent strings, URLs and HTTP status codes
Tools in this hub
IPv4 Subnet Calculator
CIDR calculator: network, broadcast, host range, mask, wildcard for /0-/32. Supports IPv4, subnet. Local computation for sysadmins. Free at oltool.net.
IPv4 Range Expander
Expand CIDR notation to a list of IP addresses with bulk export. Supports IPv4 range, CIDR expand. Local computation for sysadmins. Free at oltool.net.
IPv4 Address Converter
Convert IPv4 between dotted, decimal, hex and binary formats with reverse DNS. Supports IPv4 converter, IP address. Local computation for sysadmins. Free at oltool.net.
IPv6 ULA Generator
Generate IPv6 unique local addresses (fd00::/8) with custom subnet and EUI-64. Supports IPv6, ULA. Local computation for sysadmins. Free at oltool.net.
MAC Address Generator
Generate random MAC addresses with optional vendor prefix and colon/hyphen separators. Supports MAC address, MAC generator. Local computation for sysadmins. Free at oltool.net.
MAC Address Vendor Lookup
Look up MAC OUI vendor from address prefix using IEEE database. Supports MAC vendor, MAC lookup. Local computation for sysadmins. Free at oltool.net.
Random Port Generator
Generate random valid non-system port numbers (1024-65535) with bulk export. Supports port, random port. Local computation for sysadmins. Free at oltool.net.
User-Agent Parser
Parse User-Agent strings into browser, OS and device info with Chrome, Firefox, Safari detection. Supports User-Agent, UA parser. Local computation. Free at oltool.net.
URL Parser
Parse a URL into protocol, host, path, query, hash components with query parsing. Supports URL parser, URL components. Built for developers, works offline. Free at oltool.net.
HTTP Status Codes
Reference for HTTP status codes (1xx-5xx) with meanings and examples. Supports HTTP status, HTTP code. Built for developers, no signup, works offline. Free at oltool.net.
Device Information
Display browser, OS, screen, GPU and runtime info with viewport and pixel ratio. Supports device info, browser info. Built for developers, works offline. Free at oltool.net.
Phone Parser & Formatter
Parse, validate and format international phone numbers with E.164 and country codes. Supports phone number, phone parser. Local computation for sysadmins. Free at oltool.net.
Suggested workflows
Subnet planning
Calculate a subnet, expand the range and convert IP address formats.
Device diagnostics
Generate or inspect MAC addresses, then pair device info with User-Agent parsing.
API troubleshooting
Parse URL parts, check HTTP status codes and reserve usable ports.
How to use this network hub
One place for related diagnostics
IP, ports, URLs, status codes and client details often appear in the same troubleshooting session.
Quick calculations without setup
Get subnet ranges, address conversions and text parsing without installing command-line utilities.
Useful in restricted environments
Local processing keeps core calculations and parsing available even when network access is limited.
Network tools FAQ
When should I use the IPv4 subnet calculator?
Use it for network planning, checking usable host ranges, validating masks and finding broadcast addresses.
Does MAC vendor lookup require internet access?
If OUI data is bundled, lookup can run locally. Coverage depends on the included dataset version.
Are User-Agent parsing results always accurate?
No. User-Agent strings can be spoofed, so parsed results are helpful signals but not security guarantees.