Netflix and YouTube are both reducing video-streaming quality in Europe to reduce the stress on residential broadband networks caused by the coronavirus pandemic forcing people to stay home.

Netflix is reducing the bit rate on video streams, but not the resolution, for the next 30 days in the EU and UK, the BBC reported. The BBC said that "movies will still be high-definition or ultra-high definition 4K" despite the bit-rate decrease, but other news sources suggest that resolution could be cut, too. It's not clear what the exact changes in bit rates are—we asked Netflix to clarify these points but haven't gotten an answer yet.

After discussions with a European government official who called for lowered video quality, "Netflix has decided to begin reducing bit rates across all our streams in Europe for 30 days," Netflix said in a statement quoted by The Verge. "We estimate that this will reduce Netflix traffic on European networks by around 25 percent while also ensuring a good quality service for our members."

The Verge article also noted that "if bandwidth is low, videos will automatically stream at a lower resolution."

YouTube seems to be taking a slightly different approach. "We are making a commitment to temporarily switch all traffic in the EU to standard definition by default," YouTube said in a statement quoted by Reuters today. YouTube owner Google told Ars that the change will be in place in the EU and UK for 30 days.

Standard definition generally means 480p, or DVD quality. But YouTube's statement that videos will stream in "standard definition by default" means that users can keep using the toggle on each video to switch to a higher resolution. Google confirmed to Ars that users can still manually adjust the quality of any video they watch on a computer, TV, or mobile device. Making 480p the default would still reduce overall broadband-data usage significantly, even if many users switch to higher resolutions.

Google told Ars that YouTube has "seen only a few usage peaks," and has "measures in place to automatically adjust our system to use less network capacity." We asked Netflix if it has seen any performance problems. We also asked Netflix and YouTube whether they plan to make similar changes in the US as the pandemic goes on. We'll update this story if we get any more details.

Usage up, but networks have extra capacity

Just how necessary these steps are isn't clear, but Netflix and Google were under pressure to make the change. Thierry Breton, a French politician who is the European commissioner for Internal Market and Services, tweeted that he spoke with Netflix CEO Reed Hastings to urge a switch to standard definition. Breton also spoke with Google officials, Google told Ars.

"Teleworking and streaming help a lot but infrastructures might be in strain," Breton wrote. "To secure Internet access for all, let's #SwitchToStandard definition when HD is not necessary."

UK-based Internet provider BT said today that despite the recent increase in broadband usage, "we have plenty of headroom for it to grow still further." UK-based ISPs Vodafone and TalkTalk also said they have enough capacity.

In normal times, residential broadband networks have relatively low usage during the day and spikes at night when people are home and watching streaming video. What matters most is the ability to handle peak loads; if a network has more than enough capacity to handle the usual nighttime peaks, they may be able to handle pandemic levels of traffic without much of a problem. In the US, we'd expect cable and fiber networks to handle the surge pretty well, but old DSL networks and satellite services are a different story because those networks have capacity problems even in normal times.

Comcast and AT&T have temporarily suspended data-cap enforcement because of the pandemic, which could increase bandwidth usage. But data caps and overage fees are a revenue-generation tool rather than an effective system for managing congestion. Some major ISPs such as Verizon and Charter don't even bother with data caps, so they didn't have to make any changes on that front. (Charter is prohibited from selling plans with data caps and overage thanks to a merger condition imposed on its 2016 purchase of Time Warner Cable, and that merger condition expires in 2023.)

According to a BroadbandNow analysis published Tuesday, "home Internet connections [are] holding steady in most major US cities amid [the] mass shift to remote work."

Cloudflare examined Internet-usage patterns in European countries and found increased usage both on last-mile networks and at the Internet exchange points at which ISPs exchange traffic with each other. But while Internet usage is rising 10 to 40 percent depending on the country, "big changes in Internet traffic aren't unusual," often "occur[ring] around large sporting events like the Olympics or World Cup, cultural events like the Eurovision Song Contest and even during Ramadan at the breaking of the fast each day," Cloudflare wrote.

"Even though from time to time individual services—such as a website or an app—have outages, the core of the Internet is robust," Cloudflare wrote. "Traffic is shifting from corporate and university networks to residential broadband, but the Internet was designed for change."

This article was updated with comments from Google.

Disclosure: The Advance/Newhouse Partnership, which owns 13 percent of Charter, is part of Advance Publications. Advance Publications owns Condé Nast, which owns Ars Technica.