Internet Speed Test: download, upload & latency
Free in-browser internet speed test against Cloudflare's global anycast edge. Measures download, upload and latency / jitter. No signup, no third-party tracking — just the same public endpoints Cloudflare's own speed test uses.
Powered by Cloudflare's official measurement engine — parallel TCP streams, loaded-latency, jitter and packet loss. A full run uses ~80 MB of bandwidth.
When to run an internet speed test
Diagnose slow Wi-Fi
Run the test from different rooms to find dead zones. If wired speed beats Wi-Fi by 3× or more, you have an access-point problem.
Verify your ISP
Compare measured Mbps to the plan you pay for. Consistent gaps under 70% of the advertised speed are worth a support ticket.
Gaming & video calls
Watch the loaded-latency and jitter numbers — those, not raw Mbps, predict Zoom, FaceTime and online-gaming quality.
Streaming & 4K
Netflix 4K needs ~25 Mbps down, YouTube 4K ~20 Mbps, Apple TV+ ~25 Mbps. This test tells you instantly if you have headroom.
Cloud backup & uploads
Upload speed often gets ignored. Backing up 100 GB to iCloud or Dropbox at 5 Mbps takes ~46 hours; at 50 Mbps it's 4½.
5G vs Wi-Fi on mobile
Test on cellular and Wi-Fi back-to-back to see which is actually faster — modern 5G often beats home broadband.
How to use the internet speed test
Close other heavy tabs
Pause big downloads, streaming and cloud sync. They share your link and will skew the numbers downward.
Pick a mode
Full runs the complete Ookla-grade suite (download, upload, latency under load, packet loss) and uses ~80 MB. Quick trims to latency + download.
Click Start speed test
The Cloudflare engine warms up the connection, opens parallel TCP streams, then probes each phase in turn. Numbers fill in live.
Read the results
Download / upload in Mbps. Latency (idle) is your baseline ping. Loaded latency is ping while the line is saturated — high values mean bufferbloat. Jitter over 30 ms hurts voice and games.
About this internet speed test
This internet speed test is powered by Cloudflare's official measurement engine — the same library that drives speed.cloudflare.com. It runs entirely in your browser against Cloudflare's global anycast edge (300+ POPs worldwide) and measures the metrics that actually predict real-world experience, not just the headline Mbps number.
Download & upload speed (Mbps)
The engine opens several parallel TCP streams against the nearest Cloudflare POP, ramps up over progressively larger payloads (10 KB → 25 MB), then takes the 90th-percentile bandwidth across a warmed-up window. Single-stream tests (the old approach) consistently under-report speeds above ~200 Mbps; multi-stream matches what your operating system can actually achieve.
Latency, jitter & loaded latency
Unloaded latency is the round-trip time when your link is idle — the classic "ping". Jitter is the standard deviation of those round-trips — a steady 40 ms is way better than 30 ms ± 80 ms. Loaded latency is the same ping measured while the download or upload is saturating your line. If loaded latency balloons to 200 ms+, you have bufferbloat — your router is queueing packets instead of dropping them, which makes Zoom, gaming and even regular browsing feel laggy during any background transfer.
Packet loss & AIM score
Packet loss is measured via STUN/TURN over UDP. On cellular and locked-down networks the probe can fail entirely — that's normal and the rest of the test still completes. The AIM score (Aggregated Internet Measurement) is Cloudflare's composite quality rating across streaming, gaming and conferencing scenarios — a single number from 0 to 100 you can compare across runs.
What's a "good" result?
Casual browsing and HD video: 10 Mbps down is fine. 4K streaming: 25 Mbps. Two simultaneous 4K streams + a video call: 50 Mbps. Gaming wants latency under 50 ms and jitter under 15 ms; video calls want loaded latency under 150 ms. If your numbers are way below your plan, run the test wired (Ethernet) — Wi-Fi caps and interference hide a lot of broadband performance.
Privacy & data use
Nothing is recorded server-side beyond the standard Cloudflare access logs for the measurement endpoints. Full mode transfers about 80 MB; Quick mode about 15 MB. Cellular users on metered plans should run Quick instead.
Internet Speed Test — frequently asked questions
It measures throughput between your browser and Cloudflare's global anycast edge — the same endpoints used by speed.cloudflare.com. Results are close to what you'd see in their official test, with the caveat that browser overhead adds a small floor.
Residential and mobile internet plans are typically asymmetric — downstream gets more bandwidth than upstream. Fiber and business plans are usually symmetric.
Under 30 ms for the same continent, under 80 ms across an ocean. Gaming wants under 50 ms; video calls under 150 ms; web browsing barely cares.