The Methodology

How we verify that an Internet Provider can consistently serve YouTube in HD.

The Ratings

What do the ratings mean?

The ratings represent the video streaming quality you can expect (at least 90% of the time) when you watch YouTube on an Internet Service Provider in a specific area.

  • YouTube HD Verified: Users on YouTube HD Verified networks should expect smooth playback most of the time when watching high-definition YouTube videos (720p and above).
  • Standard Definition: Users on networks rated as Standard Definition should expect smooth playback on standard-definition YouTube videos (360p) and may experience occasional interruptions on high-definition YouTube videos (720p and above).
  • Lower Definition: Users on networks rated as Lower Definition may experience fuzzy picture quality and frequent interruptions while playing YouTube videos at 360p and above.

Why is the data useful?

Rather than being based on data from a small sample of users, this report is based on billions of YouTube videos watched across thousands of ISPs.

  • We look at how quickly all YouTube video data was loaded over the last 30 days.
  • We segment the results by ISP and by geographical location.
  • We determine what the minimum available speed was at least 90% of the time.

How do you protect my privacy?

This is anonymized data about everyone watching YouTube on an ISP.

  • Ratings are centered around networks, not users.
  • All samples are completely anonymized and no user information is stored or used.
  • We will only show the results for a geographic area big enough to have a lot of users.


There are many factors that can independently affect user experience on the internet, including - but not limited to - a user's internet connection speed, reliability of the access network, availability and load characteristics of the application servers and in some cases, the configuration of the users' in-home network. Individual and isolated measures like access speed or server capacity do not capture the real user experience. An end to end, application-level performance measurement that includes all the influencers in the equation is the right approach to measure and quantify the true internet user experience.

Presented here is a methodology to rate Internet Service Providers (ISPs) in terms of YouTube video capability, based on sustained application level performance measurements. The objective is to present a rating that is meaningful, easy to understand and one that closely reflects the real world internet experience.



A typical YouTube video playback consists of a YouTube client (player) fetching video bytes in a streaming fashion from a YouTube server (CDN), in one or more requests (e.g. HTTP GET). The first step in determining ISP ratings is to measure the sustained speed at which these video bytes are transferred from server to the client. To measure the achieved application level throughput (goodput), the following are recorded for each request:

  1. 1) Request Identity: The originating request's timestamp, access network (e.g. network block, autonomous system number of ISP) and the coarse geographical location (e.g. country, metro), derived from client attributes such as IP address, User Agent, etc. Note that the IP to location translation done by our automated systems may return a location that is incorrect for some users.
  2. 2) Response Size: The number of application bytes (including application headers but excluding any kernel level overhead) transferred by the server to the client, in response to the request.
  3. 3) Response Time: The time taken to service the request by server, including network transmission time (all bytes acknowledged by the receiver).

Based on these measurements, the goodput for a given request 'R' is computed using the formula below. Each measured request is considered a goodput sample.

= Response Size
/ Response Time


Ratings are derived by aggregating relevant goodput samples recorded in the measurements phase. The methodology supports ratings to be computed at various levels of granularity, for the selected dimensions. For example, the rating for an ISP could be calculated for various time slices (e.g. hour, day, week, month) and/or at various geographical levels (e.g. country, province, metro, city).

For a given time period 'T' (e.g. trailing 30 days) and a geographical location 'L' (e.g. San Francisco, CA, USA), the rating for an ISP 'P' (e.g. Comcast) is computed as follows:

  1. 1) Aggregate relevant samples: Collect all goodput samples that are identified with 'T', 'L' and 'P'. i.e. requests that were originated from within the target ISP, from the target location in the target timeframe.
  2. 2) Compute GAT Volume (Goodput Above Threshold): Place each goodput sample in one of the three capability buckets - HD (High Definition), SD (Standard definition) or LD (Lower definition) based on the goodput thresholds specified in the table below. This provides the raw aggregated GAT Volume for the selected dimensions.
GAT Bucket Goodput Threshold
HD > 2.5 Mbps
SD 0.7 to 2.5 Mbps
LD < 0.7 Mbps
HD Samples SD Samples LD Samples Volume (GAT)
  1. 3) Define Rating Criteria: The ISP rating criteria is defined in terms of minimum level of GAT volume requirement for each rating level. Since this metric is designed to reflect consistency and reliability of the ISP's network, the bar needs to be set at a level that captures sustained performance rather than typical (average) performance. To that effect we define three rating scales: GAT-90 (90% of requests above threshold), GAT-95 (95% of requests above threshold), GAT-99 (99% of requests above threshold) to reflect different levels of reliability.

    The following table defines the criteria used to determine the final ISP rating in our methodology, using GAT-90. The 90% bar is chosen after careful consideration of observed practical performance in the field. The bar will closely follow the evolving network capability over time.

Rating Criteria (GAT-90)
HD 90+% samples are
marked HD
SD 90+% samples are
marked at least SD
LD Neither of the Above
  1. 4) Assign Rating: Stack the three GAT buckets from step 2 to convert raw GAT volume into GAT percentage. Determine the final rating using the criteria defined in step 3. In the illustration below, the assigned rating is SD (standard definition) since 90% or more requests meet this criteria. (i.e. the network is capable of offering at least SD quality for more than 90% of the served requests.)
0% 20% 40% 60% 80% 100% SD Rating at 90%


The ratings are centered around networks, not users. All goodput samples are completely anonymized and no user information (e.g. browser cookies, IP address) is persisted or used directly in the rating algorithm. Furthermore, if the aggregated sample volume for the selected geo level and time interval is below a certain threshold, the algorithm would fall back to using more coarse grained dimensions (i.e. aggregate by broader geo and/or time interval) that meet the minimum size requirements to compute the rating.