About

NetDiag+ is made by Dmytro Tishchenko, an independent iOS developer. It grew out of a simple frustration: every tool said the connection was fine while calls stuttered and games lagged, and none of them could say whose fault it was.

So the app measures instead of guessing — raw ICMP and TCP from the phone, the router checked separately from the internet, jitter and loss shown next to latency — and the guides on this site explain how to read those numbers. 27 tools, 13 languages; every measurement runs on the device and the results stay in its History.

How the numbers are produced

Every measurement runs on the phone, with no server of mine in the path. Ping is raw ICMP over an unprivileged datagram socket, so it needs no jailbreak and no special entitlement; when a network filters ICMP — most mobile carriers do — the tool retries over TCP on the port the host actually speaks and says so in the row, rather than reporting a false timeout.

Two habits matter more than the protocol. The first is that the router is measured separately from the internet: if the first hop is already slow, every remote number is inflated, and the app says that out loud instead of letting you blame a game server. The second is that a row reports the median of eleven attempts, not an average, with jitter and loss beside it. One outlier moves an average and cannot move a median, and a connection at 40 ms with 30 ms of jitter plays worse than a steady 120 ms — an average hides exactly that.

What it will not tell you

iOS gives no raw sockets, so replies arrive without their IP header and a traceroute cannot report the TTL a hop sent back. Nothing samples in the background: measurements exist while a tool is open. In-game latency is not the same number as a ping to the same region, because games add their own tick rate and buffering on top. And on a cellular link the queue belongs to the carrier — the app can prove it is there, and can do nothing about it. Where a limit like this exists, the guides name it.

Who it is for

People who have been told their internet is fine. Gamers with a speed test that reads 300 Mbit and a match that stutters, remote workers whose calls break up while a backup uploads, and anyone about to open a ticket with an ISP who needs something more durable than a screenshot. The evidence guide exists because a dated series of measurements gets a ticket past first-line support and a single reading does not.

How it got here

Shipped in the open, one problem at a time:

• 1.4.5 — bufferbloat test: pings the router and the internet at the same time under load, grades A to F and names who is queueing.
• 1.4.6 — Latency Dashboard: the game regions, CDN edges and carriers that matter in your country, sorted worst first, router checked first. Text export from every tool for ISP tickets.
• 1.4.7 — measurement notes in all 13 languages; deep links so a guide can open the right tool.
• Next — an Android build, and per-country endpoint tables for more markets.

Contact

Questions, bug reports, a number that looks wrong: support@netdiag.online · @Tischenkod80

Free · 27 tools · one-time purchase removes ads · no subscription