Eilmeldung vs. Sondermeldung
While both Eilmeldung and Sondermeldung deal with urgent information, they differ significantly in medium and gravity. Eilmeldung focuses on the speed of digital delivery, whereas Sondermeldung refers to an interruption of a scheduled broadcast.
Eilmeldung
B1This word translates best to "breaking news" or "flash news" and is derived from "Eile" (haste). An Eilmeldung is a short update designed to be distributed as quickly as possible, mostly seen as push notifications on smartphones or red banners on websites.
Ich habe die Eilmeldung auf meinem Handy gesehen, kurz nachdem es passiert ist.
(I saw the breaking news on my phone shortly after it happened.)
Die Zeitung sendete eine Eilmeldung über den Rücktritt des Ministers.
(The newspaper sent out a breaking news alert about the minister's resignation.)
Heutzutage bekommen wir fast jeden Tag eine neue Eilmeldung.
(Nowadays, we get a new piece of breaking news almost every day.)
Bitte schalten Sie die Benachrichtigungen für die Eilmeldung aus.
(Please turn off the notifications for the breaking news.)
Sondermeldung
B2This word translates to "special bulletin" or "special announcement" and comes from "sonder" (special/separate). A Sondermeldung implies that a TV or radio station has stopped its regular programming to report on a major event, carrying a weight of high significance or gravity.
Das laufende Fernsehprogramm wurde für eine Sondermeldung unterbrochen.
(The ongoing TV program was interrupted for a special bulletin.)
Eine Sondermeldung im Radio warnte die Bevölkerung vor dem Hochwasser.
(A special announcement on the radio warned the population about the flood.)
Früher bedeutete eine Sondermeldung oft den Ausbruch eines Konflikts.
(In the past, a special bulletin often meant the outbreak of a conflict.)
Der Sprecher verlas die Sondermeldung mit ernster Stimme.
(The announcer read the special bulletin with a serious voice.)
Summary
In short, use Eilmeldung for the fast, frequent updates you see on apps and news tickers. Use Sondermeldung for rare, major announcements that disrupt the flow of regular broadcasting media like TV or radio.