JA Technology Solutions
Networking Tools
Tools for network administration, infrastructure work, and email deliverability. Calculate IPv4 and IPv6 subnets, convert addresses, audit firewall ranges, decode MAC addresses, check SPF/DMARC/DKIM, and look up domain and IP ownership via RDAP.
Subnet Calculator
Calculate network ranges, masks, host counts, and CIDR notation for IPv4 subnets.
NetworkingIPv6 Subnet Calculator
Calculate IPv6 prefixes, expanded and compressed notation, network and host portions, and total addresses.
NetworkingIP Address Converter
Convert IPv4 addresses between dotted, decimal, hex, octal, and binary representations.
NetworkingCIDR Range & Overlap Tool
Detect overlaps between CIDR blocks, merge adjacent ranges, and check IP containment.
NetworkingMAC Address Tool
Format, validate, and look up vendor for MAC addresses across all common notations.
NetworkingEmail Auth Checker
Check SPF, DMARC, DKIM, MX, and BIMI records for any domain in one place.
NetworkingWHOIS Lookup
Look up domain and IP ownership using the modern RDAP protocol — registrar, expiry, name servers, ASN.
NetworkingDNS Lookup
Query any DNS record type (A, AAAA, MX, TXT, NS, SOA, CAA, SRV, PTR) directly from your browser.
NetworkingDNS Propagation Check
Query Cloudflare, Google, OpenDNS, and NextDNS in parallel and flag any resolver whose answer differs from the majority.
NetworkingReverse DNS + FCrDNS Checker
Look up the PTR record for an IP and verify the round-trip (FCrDNS) — important for mail server reputation.
NetworkingDNSBL Check
Check an IPv4 address against 12 public DNS blacklists in parallel and see exactly which lists flagged it.
NetworkingASN Lookup
Look up ASN, AS name, announced prefix, country, and registry for any IPv4 or IPv6 address.
NetworkingHTTP Header Inspector
Fetch any URL and see its response headers, redirect chain, and a full security-header audit (HSTS, CSP, X-Frame-Options, and more).
NetworkingSSL Certificate Checker
Check HTTPS reachability and certificate history for any hostname via Certificate Transparency logs.
NetworkingAll tools run entirely in your browser. Your data never leaves your machine. Need help? Ask James.
Other Tool Categories
Data & Finance
Banking, accounting, healthcare, payments, and EDI file formats.
Retail & POS
Barcodes, point-of-sale files, retail math, and fiscal calendars.
Shipping & Logistics
Freight estimation, container loading, route optimization, and trade compliance.
Inventory & Warehouse
Reorder planning, cycle counting, warehouse slotting, and cost allocation.
Development
Format converters, encoders, hashes, regex, JWT, SQL, and more.
IBM i & Mainframe
EBCDIC, packed decimal, COBOL copybook, DDS, BMS, and fixed-width.