diff --git a/test/utf8.c b/test/utf8.c
new file mode 100644
index 00000000..4838e897
--- /dev/null
+++ b/test/utf8.c
@@ -0,0 +1,31 @@
+// 25 may 2020
+#include "test.h"
+
+// Do not put any test cases in this file; they will not be run.
+
+const char testUTF8Empty[] = { 0 };
+const char testUTF8ASCIIOnly[] = { 0x74, 0x65, 0x73, 0x74, 0 };
+const char testUTF8WithTwoByte[] = { 0x74, 0xC3, 0xA9, 0x73, 0x74, 0 };
+const char testUTF8WithThreeByte[] = { 0x74, 0xE2, 0x93, 0x94, 0x73, 0x74, 0 };
+const char testUTF8WithFourByte[] = { 0x74, 0xF0, 0x9D, 0x90, 0x9E, 0x73, 0x74, 0 };
+// TODO document that libui does not do any sort of Unicode normalization; TODO test that (the below is adequate for canonicalization tests vs WithTwoByte above)
+const char testUTF8Combined[] = { 0x74, 0x65, 0xCC, 0x81, 0x73, 0x74, 0 };
+const char testUTF8InvalidInput[] = { 0x74, 0xC3, 0x29, 0x73, 0x74, 0 };
+const char testUTF8InvalidOutput[] = { 0x74, 0xEF, 0xBF, 0xBD, 0x29, 0x73, 0x74, 0 };
+
+// TODO figure out if strcmp() is adequate for this
+bool utf8equal(const char *s, const char *t)
+{
+	for (;;) {
+		if (*s == 0 && *t == 0)
+			return true;
+		if (*s == 0 || *t == 0)
+			return false;
+		if (*s != *t)
+			return false;
+		s++;
+		t++;
+	}
+}
+
+// TODO utf8diff