In chrome dev tools, what is the speed of each preset option for network throttling?

Question

Since a recent update to chrome, the presets are no longer labelled with bandwidth.

Chrome used to list the actual speed of each one so you could simply tell.

What bandwidth or latency do the options here represent?

Hypoderma

Same question here. Unfortunetly the description of Slow 3G and Fast 3G in the dev tool release notes is not very helpful. developers.google.com/web/updates/2017/05/… – Pimbley

Answer 1

I did some measurements with two speed tests available in the internet. With the following custom profile I received similar download speed and ping latency as with the presets.

Slow 3G Custom: Download 376 kb/s, Latency 2000 ms
Fast 3G Custom: Download 1500 kb/s = 1.5 Mb/s, Latency = 550 ms

The actually download speed measured via the speed tests was only slightly below the configured values. The measured ping latency was half of the value configured in the custom profile.

Pimbley

Answer 2

Here is an old screenshot with the details

Broider

Reference of the screenshot at Google Developers website – Nero

Answer 3

Here is a csv of the values in the screenshot from Robroi2000's answer

Preset,download(kb/s),upload(kb/s),RTT(ms)
GPRS,50,20,500
Regular 2G,250,50,300
Good 2G,450,150,150
Regular 3G,750,250,100
Good 3G, 1000,750,40
Regular 4G, 4000,3000,20
DSL 2000, 1000,5
WiFi 30000,15000,2

Striated

Just a small mention, the upload speed for the WiFi is wrong I guess. It should've been 15,000 instead of 150,000 – Sumptuous

Answer 4

From Chrome DevTools’ source code, here are the presets:

export const OfflineConditions: Conditions = {
  title: i18nLazyString(UIStrings.offline),
  i18nTitleKey: UIStrings.offline,
  download: 0,
  upload: 0,
  latency: 0,
};

export const Slow3GConditions: Conditions = {
  title: i18nLazyString(UIStrings.slowG),
  i18nTitleKey: UIStrings.slowG,
  download: 500 * 1000 / 8 * .8,
  upload: 500 * 1000 / 8 * .8,
  latency: 400 * 5,
};

export const Fast3GConditions: Conditions = {
  title: i18nLazyString(UIStrings.fastG),
  i18nTitleKey: UIStrings.fastG,
  download: 1.6 * 1000 * 1000 / 8 * .9,
  upload: 750 * 1000 / 8 * .9,
  latency: 150 * 3.75,
};

Sym

What are the units? bps? That would make Slow 3G 51.2 kbps – Cristal

I think it’s more like bytes per second due to / 8 to convert the number of bits to the number of bytes. – Sym

The unit for download and upload in the code is bytes per s, even tho the interface in chrome shows kilo bits per s. The calculation in the code e.g. for Fast3GConditions.download means 1.6 (Mb/s) * 1024 (to kilo bits) * 1024 (to bits) / 8 (to bytes) * .9 (10% bandwidth loss), which turns 1.6 Mb/s (3G datasheet bandwidth) into 188743 B/s (3G realistic bandwidth). – Scalene

Chrome should definitely adds these values in the UI, although read-only – Vinaigrette

@Vinaigrette IIRC, they used to but since removed – Sym

I'm seeing the units is all over the place. I agree that the units in the code are MB/s due to / 8. And the Throttling Profiles list shows the units as MB/s, however, when adding a new profile the input fields show kilobits per second, but inputting 10000kbps gives 10 MB/s…which is wrong…so it's a mess and very confusing. I guess it's a bug? Oh, and the old screenshot posted in another answer shows the listed units in bits so the labels got changed at some point! – Saccharase

It's 2023, why doesn't Chrome dev team add 4G/5G by default? – Avra

Answer 5

For anyone who is wondering how much time it will take to download/Upload 1 MB on connections, following are the results base on Roboroi's Screenshot

Time to download 1 MB

(1MB = 8Mb = 1024 Bytes = 8192 bits)

CONNECTION TYPE                       DOWNLOAD_TIME      UPLOAD TIME

Regular 2G (250Kb/s⬇ 50Kb/s⬆) ->       33s                163 (2m 43s)
Good 2G (450Kb/s⬇ 150Kb/s⬆) ->         18s                54s
Regular 3G (750Kb/s⬇  250Kb/s⬆) ->     11s                32s
Good 3G (1Mb/s⬇ 750Kb/s⬆) ->           8s                 11s
Regular 4G (4Mb/s⬇ 3Mb/s⬆) ->          2s                 3s
Wifi (30Mb/s⬇ 15Mb/s⬆) ->              0.27s              0.53s

Brewage

Is it possible to get the speeds of 5G or is it to early to do any concrete estimates? I saw one article that said up to 100-300Mb with a peak of 1GB download speed but that seems a bit optimistic. – Trapp

Answer 6

As mention in @Thai's answer, from the Chrome source code, just to summarise the two current network throttling options are (note that in the code the throughputs are in Bytes/sec so I have converted them to bits/sec):

          download   upload      latency
Slow 3G:  400Kbit/s  400Kbit/s   2000ms
Fast 3G:  1.44Mb/s   84.375Kb/s  562.5ms

Linnell