Internet & Networking
Download Time Calculator
Estimate a file's download duration from its size and transfer speed. Match the displayed units, then compare the theoretical result with a rate you expect to sustain.
Upload Time Calculator
Estimate the transfer time for a video, backup or shared file. Use the upload rate rather than the download rate, and enter the total size of the data that must leave your device.
Mbps to MB/s Converter
Convert megabits per second to megabytes per second, or reverse the calculation. Use the result to compare an internet rate with a file-transfer rate without mixing bits and bytes.
Data Usage Calculator
Estimate data transferred during repeated sessions from an average bitrate and duration. Read the total in GB and GiB, then compare it with an optional data allowance.
Modem Rent or Buy Calculator
Compare equipment rental charges with a one-time purchase and setup cost over your chosen number of months. Enter your own prices; the calculation does not select a modem or recommend a purchase.
Wi-Fi Free-Space Path Loss Calculator
Calculate the reference loss between two antennas from frequency and distance. This free-space model helps compare ideal radio paths. It does not scan Wi-Fi, measure signal power, map a room or predict indoor coverage.
VPN Speed Loss and Gain Calculator
Compare two entered speed readings, one without the VPN and one with it. See the signed change, relative change and retained percentage. This page performs arithmetic; it does not run a speed test or contact the VPN.
CGNAT and Double NAT Address Checker
Compare a router’s WAN IPv4 with a public IPv4 reading from the same connection. Address ranges and a mismatch provide clues about upstream translation. They do not confirm CGNAT, count NAT layers or test open ports.
2.4 GHz Wi-Fi Channel Overlap Checker
Compare the nominal frequency spans of two manually entered 2.4 GHz channels. The result shows centre spacing and span overlap. It does not scan nearby networks, measure interference or recommend the best channel.
Internet Speed Test
Run a short download and upload test between this browser and Savvy Toolkit’s server. Start controls the test; opening the page does not begin transfers. Results describe this route and endpoint, rather than the maximum speed of an internet plan.
HTTP Latency and Jitter Test
Measure repeated HTTP round-trip times between this browser and Savvy Toolkit’s server. See mean and median response times and the mean absolute change between adjacent readings. This page uses HTTP requests, rather than ICMP ping or one-way packet timing.
VPN Connection Troubleshooter
Choose the VPN symptom observed on the device and review the next checks. This guide organises manual observations; it cannot inspect the VPN app, read a profile, test an account or scan the network. Passwords, recovery codes and configuration secrets are not needed.
IPv4 Subnet Calculator
Calculate an IPv4 block from an address and CIDR prefix. Read the subnet mask, boundary addresses and conventional host positions without scanning a network. The results describe address arithmetic, not devices currently connected or addresses available for allocation.
DNS Lookup
Query Google Public DNS for one public domain name and record type. Choose A, AAAA, CNAME, MX, NS, TXT or SOA, then start the lookup. Read the resolver response with its source and query time; this is not a worldwide propagation check.
What Is My IP?
See the public address observed for a request from this browser to ipify. Start the check yourself, copy the result and compare it after changing a connection or VPN.
IP Address Lookup
Look up a public IPv4 or IPv6 address in regional Internet registry records. See its registered network, holder and address range, with a link to the original record.
PoE Switch Power Budget Calculator
Compare a switch’s PoE budget, reserve, physical ports and per-port limit with documented PSE allocations for identical devices.