154 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
Email deliverability & domain security check — validates SPF, DKIM (multi-selector), and DMARC, detects spoofing and misconfigurations, and returns an A–F email security grade with transparent deductions. Anti-spam / ant...
Bandwidth of a VoIP call (IP and Ethernet level) for a codec and packetization time, and totals for many calls.
CIDR calculator. Details of an IPv4 network in CIDR notation: network and broadcast address, first and last usable host, netmask, number of addresses, and whether a given IP falls inside. Use for firewall rules and allow...
Cron expression explained in plain English with the next run times in any time zone - validates a 5-field cron and handles DST
IPv4/IPv6 subnet calculator: network, mask, wildcard, broadcast, first/last host, usable hosts, address type (private, public, loopback...) and whether a given IP belongs to the subnet.
IPv4/IPv6 subnet calculator: network, mask, wildcard, broadcast, first/last host, usable hosts, address type (private, public, loopback...) and whether a given IP belongs to the subnet.
Check the TLS certificate a domain serves on port 443: whether it chains to a trusted root, matches the name (RFC 9525) and when it expires, with issuer, chain, key and signature algorithm, TLS version and coded findings...
Parse an IPv4 CIDR block: network address, broadcast, first/last host, netmask, and host count. Optionally test if an IP is inside it.
Resolve ENS (.eth) on Ethereum and Basenames (.base.eth) on Base, forward or reverse. Returns address, name, source, forward_verified, optional avatar.
Check whether an IP is inside a CIDR network for $0.001 USDC. Call when you need this bounded result without an API key or subscription. Returns machine-readable JSON via x402 on Base or Solana. Limitation: results cover...
Expand a CIDR block into network address, broadcast, netmask, wildcard, usable host range and host count. Pure CPU, instant. Use to plan a subnet or test whether an IP is in range.
Parse and classify an IPv4/IPv6 address (private, loopback, CGNAT, documentation, ...). Canonical and expanded forms, integer and hex values, version, scope per the IANA special-purpose registries (private, loopback, lin...
CIDR / subnet calculator: network and broadcast address, first and last usable host, netmask and wildcard mask, total and usable address counts for any IPv4 CIDR block. Network planning and validation. $0.01 per calculat...
IP range to CIDR converter: turns any IPv4 start-end range into the minimal list of CIDR blocks that cover it exactly, with the address count. Firewall and allowlist preparation. $0.01 per range.
Is the IPv4 address inside 104.16.0.0/12 (Cloudflare edge)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block....
Is the IPv4 address inside 172.64.0.0/13 (Cloudflare edge)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block....
Is the IPv4 address inside 1.1.1.0/24 (Cloudflare DNS)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block. $0....
Is the IPv4 address inside 8.8.8.0/24 (Google Public DNS)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block....
Is the IPv4 address inside 8.8.4.0/24 (Google Public DNS)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block....
Is the IPv4 address inside 9.9.9.0/24 (Quad9 DNS)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block. $0.01 pe...
Is the IPv4 address inside 208.67.222.0/24 (OpenDNS)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block. $0.01...
Is the IPv4 address inside 52.0.0.0/8 (Amazon (large block))? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known bloc...
Is the IPv4 address inside 3.0.0.0/8 (Amazon (large block))? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block...
Is the IPv4 address inside 18.0.0.0/8 (Amazon (large block))? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known bloc...