You can omit initial-scale=1.0 from viewport meta tag in modern browsers

The practical change is that the viewport meta tag can be reduced to just width=device-width, making the initial-scale=1.0 flag obsolete for contemporary browsers. This simplification follows years of evolution since the tag was first introduced to support the original iPhone's browser. Developers can now rely on width=device-width alone to achieve the intended layout scaling.

Historically, the initial-scale=1.0 value was added to address undesired zooming behavior that appeared in early iOS releases after the 2007 iPhone launch and in certain other browsers. The Safari Web Content Guide recommended the tag to allow desktop-designed sites to be usable on small screens via user-initiated zoom and pan. Over time, browser updates resolved those quirks, rendering the extra parameter unnecessary.

Adopting the simpler tag costs virtually nothing; it merely involves removing a few characters from the HTML head. The material notes that this saves about 19 bytes per page, a tiny amount per document but meaningful when multiplied across the vast number of pages served each day. No functional difference is expected in modern browsers when the flag is omitted.

The simplification stops being safe only when a project must still support very old iOS versions or legacy browsers that retain the original zooming bug. In those environments, dropping initial-scale=1.0 could reintroduce unwanted scaling issues. For all other cases, the reduced markup is both valid and beneficial.