In the Express Mobile, Inc. v. GoDaddy.com, LLC opinion issued by the Federal Circuit on April 2, 2025, the Court analyzed the District Court’s claim construction rulings, offering practical insights for effective patent claim drafting and prosecution.

At issue in Express Mobile were several software or information technologies terms wherein both parties argued for subtly different meanings that could have drastic effects on the enforceability of the subject patents.

In 2019, Express Mobile brought suit against GoDaddy.com for patent infringement in the U.S. District Court for the District of Delaware. The suit involved 5 of Express Mobile’s patents relating to “What-You-See-Is-What-You-Get” (WYSIWYG) web development technologies. The two patent families at issue were (1) 6,546,397 (the ’397 Patent) and 7,594,168 (the ’168 Patent) (collectively, the ’397 Patents) and (2) 9,063,755 (the ’755 Patent), 9,471,287 (the ’287 Patent), and 9,928,044 (the ’044 Patent) (collectively, that ’755 Patents). With respect to the ’397 Patents, the District Court granted GoDaddy.com’s motion for summary judgment and held that GoDaddy.com’s Website Builder (WSB) did not infringe. A jury trial was held with respect to the ’755 Patent, and the jury found GoDaddy.com did not infringe. Express Mobile appealed the decisions, arguing that the District Court had improperly construed several key claim terms at issue in the case.

The term at issue regarding the ’397 Patents was “runtime engine,” and the terms, “device-dependent code” and “registry” were at issue with respect to the ’755 Patents.

Claim 1 of the ’168 Patent recites, a “database” comprising information regarding website objects, and a “runtime engine [that] is configured to generate the web-site from the objects and style data extracted from the provided database.” Express Mobile argued for a broad construction of “runtime engine” such that it would mean a “file that is executed at runtime that utilizes information from the database and generates commands to display a web page or website.” In contrast, the District Court construed the term to mean a “file that is executed at runtime that reads information from the database and generates commands to display a web page or website.” Put another way, Express Mobile asserted the runtime engine need only use information derived from a database—the runtime engine itself need not directly interact with the database. The District Court granted GoDaddy.com’s motion for summary judgment, because the Court’s construction required that an accused “runtime engine” must directly interact with a database. Although GoDaddy.com’s accused JavaScript files rendered website content, they did not directly interact with a database.

In determining an appropriate claim construction for “runtime engine” the Federal Circuit reviewed (1) the usage of “runtime engine” in the claims; (2) the surrounding language in the claims; (3) the plain meaning of the term; (4) the related descriptions in the specification; and (5) the prosecution history. The Federal Circuit’s analysis focused on the express language in the claims that was broader on its face compared to the usage in the specification. The Federal Circuit accordingly found that the District Court’s narrower interpretation had improperly read limitations into the claims from the specification.

With respect to the ’755 Patents, Express Mobile argued that the District Court had erred in allowing GoDaddy.com to suggest to the jury improper meanings of terms such as “device-dependent code” and “registry.” The Federal Circuit held that Express Mobile should have requested further claim construction with the District Court or should have raised such issues during trial. The Court further found the jury’s verdict to be substantially supported by the evidence and therefore affirmed the District Court’s denial of Express Mobile’s motion for Judgment as a Matter of Law.

Express Mobile, Inc. v. GoDaddy.com, LLC demonstrates practical considerations that should be followed during prosecution. In particular, although selecting appropriate terms in the specification and claims can help avoid inadvertently narrow constructions, the analysis should not end after choosing the appropriate terms. The words surrounding the terms may be just as important, such as how the Federal Circuit found the meaning of “runtime engine,” as claimed, to not necessarily be limited to components that directly interact with a database. Express Mobile further demonstrates that, once at trial, any issues regarding claim construction should be timely raised, or litigants may be stuck with unfavorable constructions that cannot be remedied later.