Measure download, upload, idle and loaded latency, jitter and reliability, then turn the numbers into practical next steps. Free, private and no account required.
Run complete testExplore diagnosticsDistance to the UK server can raise latency outside nearby regions.Uses about 24 MB per completed test.
Run several tests at different times for a representative result.
These are approximate single-device estimates, not guarantees. Other users, applications, routes and service requirements can change the experience. How the estimates are interpreted →
A speed number is only a starting point. The same symptom can come from the device, Wi-Fi, local traffic, broadband line, provider route, DNS or the service itself. Use controlled comparisons to find the boundary where performance changes.
Pause large transfers and run three tests on the same device. Note the time, room, connection type and whether a VPN is active. The browser test uses real HTTPS transfers and measures the complete path to LumaProbe, not only the provider line.
Compare beside the router with the problem room, then Wi-Fi with Ethernet where possible. If wired performance is healthy but a room is poor, investigate coverage. If every device is poor on both, check official provider information and the access connection.
Upload affects calls and backups; latency affects responsiveness; jitter shows variation. Failed requests are unsuccessful HTTPS samples, not a formal ICMP packet-loss percentage. Repetition matters more than one unusually good or bad run.
LumaProbe requires no account, stores public test history only in your browser, publishes its implemented method and links to official provider checkers instead of inventing live outage claims.
Download capacity matters for large transfers and streams, but upload, idle latency, loaded latency, jitter and consistency often explain calls, games and “fast but laggy” connections better.
Idle latency is measured before a large transfer. Loaded latency is sampled while the download is busy. A large increase can reveal queueing that affects calls and games when someone else uses the connection.
Use the same device and connection type, pause avoidable traffic and repeat at different times. Compare Wi-Fi beside the router, the problem room and Ethernet before blaming the package.
Anyone can run LumaProbe, but the current test node is in the United Kingdom. Long-distance routes can add latency or limit throughput, so distant visitors should focus on repeatable comparisons.
Checks run only when you request them and explain what each result means.
See your public IP, HTTPS status and browser-reported connection type.
Learn more →Confirm that a domain resolves and compare lookup time.
Learn more →Check a public website HTTP response without opening it.
Learn more →Inspect online state, cookies, local storage and connection API support.
Speed test →Follow a short decision tree and receive targeted next steps.
Start troubleshooter →Review speed tests saved privately in this browser and export them as CSV.
Learn more →We link to verified provider pages and never invent outage reports.
A controlled way to separate broadband, coverage, interference and device problems before changing equipment.
Read guide →Buying guideChoose a router, access point or mesh system from diagnosed coverage, port and support needs—not headline speed.
Read guide →NetworkingA practical guide to Cat 5e, Cat 6, link speeds, switches, adapters and wired backhaul for home networks.
Read guide →GamingDiagnose local Wi-Fi, busy-line queueing and route problems without chasing misleading “gaming speed” claims.
Read guide →ReliabilityImprove calls and remote access, separate work and home faults, and prepare a realistic fallback before an important meeting.
Read guide →UK consumer guideUnderstand contract speed information, document a persistent fault and use the provider complaint and ADR process under current UK rules.
Read guide →Some links may earn us a commission at no extra cost to you. Recommendations are categories, not paid rankings.
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