diff --git a/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt b/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
index 94d9d755..482a1bdc 100644
--- a/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
+++ b/processor/src/main/kotlin/org/ethereum/lists/chains/Main.kt
@@ -26,6 +26,7 @@ private val allChainFiles = allFiles.filter { !it.isDirectory }
 
 private val allIconFilesList = iconsPath.listFiles() ?: error("${iconsPath.absolutePath} must contain the icon json files - but it does not")
 private val allIconFiles = allIconFilesList.filter { !it.isDirectory }
+private val allUsedIcons = mutableSetOf<String>()
 
 fun main(args: Array<String>) {
 
@@ -34,7 +35,7 @@ fun main(args: Array<String>) {
     val verbose = argsList.contains("verbose").also { argsList.remove("verbose") }
     if (argsList.firstOrNull() == "singleChainCheck") {
         val file = File(File(".."), args.last())
-        if (file.exists() && file.parentFile == chainsPath ) {
+        if (file.exists() && file.parentFile == chainsPath) {
             println("checking single chain " + args.last())
             checkChain(file, true, verbose)
         }
@@ -129,13 +130,26 @@ private fun doChecks(doRPCConnect: Boolean, doIconDownload: Boolean, verbose: Bo
         checkIcon(it, doIconDownload, allIconCIDs, verbose)
     }
 
+    val unusedIconDownload = mutableSetOf<String>()
     iconsDownloadPath.listFiles()?.forEach {
-        if (!allIconCIDs.contains(it.name)) throw UnreferencedIcon(it.name, iconsDownloadPath)
+        if (!allIconCIDs.contains(it.name)) unusedIconDownload.add(it.name)
+    }
+    if (unusedIconDownload.isNotEmpty()) {
+        throw UnreferencedIcon(unusedIconDownload.joinToString (" ") , iconsDownloadPath)
     }
-
     allFiles.filter { it.isDirectory }.forEach { _ ->
         error("should not contain a directory")
     }
+
+    val unusedIcons = mutableSetOf<String>()
+    iconsPath.listFiles().forEach {
+        if (!allUsedIcons.contains(it.name.toString().removeSuffix(".json"))) {
+            unusedIcons.add(it.toString())
+        }
+    }
+    if (unusedIcons.isNotEmpty()) {
+        error("error: unused icons ${unusedIcons.joinToString(" ")}")
+    }
 }
 
 fun checkIcon(icon: File, withIconDownload: Boolean, allIconCIDs: MutableSet<String>, verbose: Boolean) {
@@ -255,9 +269,13 @@ fun checkChain(chainFile: File, connectRPC: Boolean, verbose: Boolean = false) {
     }
 
     jsonObject["icon"]?.let {
+        if (it !is String) {
+            error("icon must be string")
+        }
         if (!File(iconsPath, "$it.json").exists()) {
             error("The Icon $it does not exist - was used in ${chainFile.name}")
         }
+        allUsedIcons.add(it)
     }
 
     val nameRegex = Regex("^[a-zA-Z0-9\\-\\.\\(\\) ]+$")
@@ -312,6 +330,10 @@ fun checkChain(chainFile: File, connectRPC: Boolean, verbose: Boolean = false) {
                 throw (ExplorerMustHaveName())
             }
 
+            if (explorer["icon"] != null) {
+                allUsedIcons.add(explorer["icon"].toString())
+            }
+
             val url = explorer["url"]
             if (url == null || url !is String || httpPrefixes.none { prefix -> url.startsWith(prefix) }) {
                 throw (ExplorerMustWithHttpsOrHttp())
diff --git a/processor/src/main/kotlin/org/ethereum/lists/chains/model/Exceptions.kt b/processor/src/main/kotlin/org/ethereum/lists/chains/model/Exceptions.kt
index 5d263f1c..647f5eb5 100644
--- a/processor/src/main/kotlin/org/ethereum/lists/chains/model/Exceptions.kt
+++ b/processor/src/main/kotlin/org/ethereum/lists/chains/model/Exceptions.kt
@@ -53,4 +53,4 @@ class ChainNameMustBeString: Exception("Name must be string")
 
 class IllegalName(type: String,name: String): Exception("Invalid $type: $name")
 
-class UnreferencedIcon(fileName: String, iconsDownloadPath: File): Exception("Found file $fileName in $iconsDownloadPath that is not referenced")
\ No newline at end of file
+class UnreferencedIcon(fileName: String, iconsDownloadPath: File): Exception("Found unreference $fileName in $iconsDownloadPath")
\ No newline at end of file