diff --git a/apps/judicial-system/web/src/utils/hooks/useFileList/index.ts b/apps/judicial-system/web/src/utils/hooks/useFileList/index.ts
index 0ab7be7464ed..5a668284561b 100644
--- a/apps/judicial-system/web/src/utils/hooks/useFileList/index.ts
+++ b/apps/judicial-system/web/src/utils/hooks/useFileList/index.ts
@@ -9,6 +9,7 @@ import {
 } from '@island.is/judicial-system-web/src/components'
 import { CaseFileState } from '@island.is/judicial-system-web/src/graphql/schema'
 
+import useIsMobile from '../useIsMobile/useIsMobile'
 import { useGetSignedUrlLazyQuery } from './getSigendUrl.generated'
 import { useLimitedAccessGetSignedUrlLazyQuery } from './limitedAccessGetSigendUrl.generated'
 
@@ -21,8 +22,13 @@ const useFileList = ({ caseId, connectedCaseParentId }: Parameters) => {
   const { limitedAccess } = useContext(UserContext)
   const { setWorkingCase } = useContext(FormContext)
   const { formatMessage } = useIntl()
+  const isMobile = useIsMobile()
   const [fileNotFound, setFileNotFound] = useState<boolean>()
 
+  const openFile = (url: string) => {
+    window.open(url, isMobile ? '_self' : '_blank', 'noopener, noreferrer')
+  }
+
   const [
     getSignedUrl,
     { error: fullAccessError, variables: fullAccessVariables },
@@ -31,7 +37,7 @@ const useFileList = ({ caseId, connectedCaseParentId }: Parameters) => {
     errorPolicy: 'all',
     onCompleted(data) {
       if (data?.getSignedUrl?.url) {
-        window.open(data.getSignedUrl.url, '_blank')
+        openFile(data.getSignedUrl.url)
       }
     },
     onError: () => {
@@ -47,7 +53,7 @@ const useFileList = ({ caseId, connectedCaseParentId }: Parameters) => {
     errorPolicy: 'all',
     onCompleted(data) {
       if (data?.limitedAccessGetSignedUrl?.url) {
-        window.open(data.limitedAccessGetSignedUrl.url, '_blank')
+        openFile(data.limitedAccessGetSignedUrl.url)
       }
     },
     onError: () => {
diff --git a/apps/judicial-system/web/src/utils/hooks/useIsMobile/useIsMobile.ts b/apps/judicial-system/web/src/utils/hooks/useIsMobile/useIsMobile.ts
new file mode 100644
index 000000000000..5afc2ea17f66
--- /dev/null
+++ b/apps/judicial-system/web/src/utils/hooks/useIsMobile/useIsMobile.ts
@@ -0,0 +1,25 @@
+import { useEffect, useState } from 'react'
+
+const useIsMobile = () => {
+  const [isMobile, setIsMobile] = useState(false)
+
+  useEffect(() => {
+    const checkMobile = () => {
+      // Check for SSR
+      if (!window) {
+        return false
+      }
+
+      const userAgent = navigator.userAgent
+      const mobileRegex =
+        /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i
+      return mobileRegex.test(userAgent)
+    }
+
+    setIsMobile(checkMobile())
+  }, [])
+
+  return isMobile
+}
+
+export default useIsMobile