Bandwidth Lab: Network Tester

Bandwidth Lab lets developers and testers see how

their apps behave on slow, unstable, or broken

connections, right on a real Android phone. No

root, no proxy setup, and no external server.

Pick a network profile, choose which apps to

affect, and tap Start. Bandwidth Lab limits

bandwidth and adds latency, jitter, and packet

loss to real traffic, so you can reproduce

bad-network bugs in seconds.

READY-MADE NETWORK PROFILES

• Fast 4G, Patchy 4G, 3G, and 2G / EDGE

• Café Wi-Fi with spiky latency

• Choppy Call for real-time audio and video

testing

• Upload Bottleneck: fast downloads, crawling

uploads

• Lift Dead Zone with repeated short outages

• Basement, Barely Connected, and Offline

SCENARIOS THAT CHANGE BY THEMSELVES

Play a timed sequence of network conditions on a

loop:

• Lift ride: good signal, dead zone between

floors, recovery

• Metro commute: station coverage, tunnel loss,

blackout, next platform

• Train journey: fast handovers between towers

• Call breaking up: a call that slowly falls apart

BUILD YOUR OWN PROFILES

Set every parameter separately for upload and

download:

• Bandwidth (kbps), or leave it unlimited

• Latency and jitter (ms)

• Random packet loss (%)

• Repeating outages: drop all traffic for X ms,

then pass it for Y ms

TARGET SPECIFIC APPS

Throttle only the apps you are testing, or every

app on the device. Your other apps keep their

normal connection.

LIVE SPEED GAUGE

Watch real download and upload throughput against

the active profile's limit while you test. Change

profiles while throttling is running and they

apply instantly.

ALSO INCLUDED

• Manual control with quick sliders

• Ongoing notification with a Stop button

• Light, dark, and follow-system themes

WHO IT IS FOR

• Android, web, and game developers testing

loading states, timeouts, retries, and offline

handling

• QA teams reproducing bugs reported on poor

networks

• Anyone checking how video calls, streaming, or

uploads cope with bad connections

HOW BANDWIDTH LAB USES THE VPN

To shape network traffic, Bandwidth Lab uses

Android's VpnService to create a VPN that runs

entirely on your device. Traffic from the apps you

choose is passed through the app on your phone,

slowed down or dropped according to the active

profile, and then sent on to its original

destination.

• There is no remote VPN server; your traffic is

never sent to us.

• The app does not record, inspect, or store your

traffic or browsing activity.

• It does not hide your IP address, bypass

restrictions, or show ads.

• The VPN only runs after you tap Start, and you

can stop it at any time.

PRIVACY

No account, no analytics, no ads, and no data

collection. Your profiles and settings stay on

your device.

GOOD TO KNOW

• Requires Android 11 or newer.

• Android allows only one VPN at a time, so other

VPN apps must be turned off while throttling.

• While throttling is active, IPv6 traffic is

blocked (apps automatically use IPv4) and ping

(ICMP) does not work.

• Speeds are measured in kbps and include packet

headers, so download speeds appear slightly lower

than the configured limit.