AnyTool
Your files never leave your device. All processing happens locally in your browser.

What can a browser-based network analyzer actually tell me?

AnyTool Network Analyzer reports only what a browser can honestly read on its own, with no third-party servers. It shows your connection’s effective type (4g/3g/…) plus coarse downlink and round-trip-time estimates from the Network Information API (Chromium browsers only — Safari and desktop Firefox don’t support it, and it says so), your live online/offline status, and freely exposed device context (CPU cores, device memory, screen, language). It also runs a same-origin latency probe — fetching a tiny asset from this app’s own host several times and reporting the median round-trip in milliseconds — plus an approximate throughput estimate. A built-in IPv4/CIDR analyzer derives network, broadcast, host range, masks, class and RFC type from any address you type. Crucially, a browser cannot ping arbitrary hosts, run traceroute, scan ports or read your public IP without a server, so this tool deliberately does none of those — everything runs locally and nothing is uploaded.

  • Network Information API: effective type, downlink & RTT estimates (Chromium only)
  • Live online/offline status and device context (cores, memory, screen, language)
  • Same-origin latency probe: median round-trip to this app’s host
  • IPv4/CIDR analyzer: network, broadcast, host range, masks, class, RFC type
  • No real ping/traceroute/port-scan/public-IP — those need a server; 100% client-side

What is

Network analyzer (browser-based)

A browser-based network analyzer surfaces the limited network and device information a sandboxed web page can read without contacting a server: the Network Information API’s effective connection type and coarse downlink/RTT estimates (where supported), online/offline status, and device context. It can also time fetches of same-origin assets to estimate round-trip latency and rough throughput to the page’s own host. It cannot ping arbitrary hosts, run traceroute, scan ports or determine the public IP, because the browser sandbox blocks raw network access and those operations need a third-party server. AnyTool implements one entirely client-side, contacting no third party.

Calculators

Related terms

Network Information APInavigator.onLineRound-trip time (RTT)Effective connection typeSame-origin request

Frequently Asked Questions

Only roughly. It can read the browser’s coarse downlink estimate (Chromium only) and time a same-origin download, but a precise speed test needs a dedicated server, which a 100% client-side tool does not use.

The Network Information API exposes a downlink estimate in Mbps and an effective type (4g/3g/…), but it is rounded and reflects recent activity rather than a live measurement, and only Chromium-based browsers provide it. To get an actual figure, AnyTool times a fetch of a small same-origin asset over a short window and converts bytes×8 over seconds to Mbps — a ballpark that is affected by caching, CDN edge location and distance to the host. A calibrated speed test (like Ookla) uses purpose-built servers and parallel streams; that requires a server, so this client-side tool reports an approximation and labels it as such.

The browser sandbox blocks raw network access, and ping/traceroute/public-IP all require a third-party server to respond, which this tool never uses.

JavaScript in a web page has no access to the operating system’s network layer, so it cannot send ICMP pings, run traceroute or scan ports. Discovering your public IP means asking an external server to echo back the address it saw — again, a third party. AnyTool is 100% client-side and contacts no such service, so it deliberately omits all of these. Instead it measures latency to its own origin and reports only information the browser already exposes, keeping the promise that nothing leaves your device.

It measures the round-trip time to this app’s own host by fetching a tiny asset several times and taking the median — not a ping to a server you choose.

The probe issues a warm-up request, then fetches a small same-origin file (about 2 KB) seven times with cache-busting query strings, recording each round-trip with performance.now(). It reports the median in milliseconds along with the best and worst samples, which smooths out one-off spikes. Because the requests go only to the origin serving this page, it reflects your latency to that host and its CDN edge — useful as a relative figure, but not a substitute for a network ping to an address of your choosing.

Partly — online status, the latency probe, device info and the IP analyzer work everywhere, but the effective-type/downlink/RTT panel needs the Network Information API, which Safari and desktop Firefox don’t implement.

The Network Information API (navigator.connection) is implemented in Chromium-based browsers (Chrome, Edge, Opera, Samsung Internet) but not in Safari or desktop Firefox. When it is missing, AnyTool shows an honest “not available in this browser” message instead of inventing numbers. The rest of the tool — online/offline status via navigator.onLine, the same-origin latency and throughput probe, the device/client panel and the IPv4/CIDR analyzer — relies on universally available APIs and works in every modern browser.

Detailed Explanation

How It Works

What a Browser Can Honestly Report About the Network

A sandboxed web page cannot reach the operating system network layer, so it cannot send ICMP pings, run traceroute, scan ports or read the public IP without a third-party server. AnyTool Network Analyzer is 100% client-side and contacts no such service, so it reports only browser-exposed signals: the Network Information API (navigator.connection) effective type and coarse downlink/RTT estimates where supported, the navigator.onLine online/offline status, and freely available device context such as CPU cores, device memory, screen and language. It deliberately omits anything that would require a server.

  • Browsers block raw network access; no ICMP ping, traceroute or port scan
  • Public IP needs an external echo server — omitted in a client-side tool
  • Network Information API gives effective type, downlink and RTT estimates
  • navigator.onLine plus online/offline events track connectivity changes
  • Device context (cores, memory, screen, language) is read locally
Methodology

How the Same-Origin Latency and Throughput Probe Works

To produce an actual measured figure without a third party, the tool times fetches to the app’s own host. After one warm-up request it fetches a tiny same-origin asset (about 2 KB) seven times with cache-busting query strings, records each round-trip via performance.now(), and reports the median in milliseconds plus the best and worst samples. A separate single fetch of a small same-origin image (about 144 KB) over a short window yields an approximate throughput in Mbps (bytes × 8 ÷ seconds). Both measure this origin and its CDN edge — not a ping to an arbitrary server — and are presented as estimates rather than calibrated results.

  • Latency: median of 7 same-origin fetches after a warm-up, in milliseconds
  • Reports median plus best/worst to expose variance
  • Throughput: one small same-origin download, bytes×8÷seconds → Mbps
  • Measures latency to this origin/CDN edge, not an arbitrary host
  • Cache-busting query strings ensure fresh fetches each sample
Limitations

Limits, Browser Support, and Privacy

The Network Information API is implemented in Chromium-based browsers (Chrome, Edge, Opera, Samsung Internet) but not in Safari or desktop Firefox; when absent the tool shows an honest unavailable message instead of fabricating numbers. The downlink and RTT it does report are coarse estimates (rounded to roughly 25 Kbps and 25 ms) reflecting recent activity, not a live line test. The probe figures are approximate and affected by caching and CDN proximity. Everything runs in the browser: no account, no tracking, no upload, and no third-party network call of any kind.

  • Network Information API: Chromium yes; Safari and desktop Firefox no
  • Downlink/RTT are coarse, rounded estimates, not live measurements
  • Probe throughput is approximate and CDN/cache dependent
  • No ping, traceroute, port scan or public-IP lookup by design
  • No account, tracking, upload or third-party call — works offline
Network diagnostics: in-browser (AnyTool) vs server-backed speed-test sites
CapabilityAnyToolServer-backed tools
Where it runs100% in your browserBrowser + their servers
Third-party callsNoneRequired
Public IPNot shown (needs a server)Usually shown
Real ping / tracerouteNo — sandbox blocks itSometimes (via server)
Connection type / RTTNetwork Information API (Chromium)Inferred from server tests
Latency probeSame-origin median RTTTo their test servers
ThroughputApproximate, same-originCalibrated, multi-stream
IP / CIDR analyzerBuilt in, offlineRarely included
PrivacyNothing uploadedData sent to their servers

AnyTool is deliberately honest: it reports only what a browser can read locally and never contacts a third party.