diff --git a/src/file-renderer/index.js b/src/file-renderer/index.js
index 5ae2d6c..594a918 100644
--- a/src/file-renderer/index.js
+++ b/src/file-renderer/index.js
@@ -1,31 +1,14 @@
 import { jDataView } from "./jdataview";
-import { pesRead } from "../format-readers/pes";
-import { dstRead } from "../format-readers/dst";
+import { supportedFormats } from "../format-readers";
 import { Pattern } from "./pattern";
-import { pecRead } from "../format-readers/pec";
-import { jefRead } from "../format-readers/jef";
-import { expRead } from "../format-readers/exp";
-
-String.prototype.endsWith = function (suffix) {
-  return this.indexOf(suffix, this.length - suffix.length) !== -1;
-};
 
 function renderToCanvas(filename, evt, canvas) {
+  const fileExtension = filename.toLowerCase().split(".").pop();
   const view = jDataView(evt.target.result, 0, evt.size);
   const pattern = new Pattern();
 
-  filename = filename.toLowerCase();
-  if (filename.endsWith("pes")) {
-    pesRead(view, pattern);
-  } else if (filename.endsWith("dst")) {
-    dstRead(view, pattern);
-  } else if (filename.endsWith("pec")) {
-    pecRead(view, pattern);
-  } else if (filename.endsWith("jef")) {
-    jefRead(view, pattern);
-  } else if (filename.endsWith("exp")) {
-    expRead(view, pattern);
-  }
+  supportedFormats[fileExtension].read(view, pattern);
+
   pattern.moveToPositive();
   pattern.drawShape(canvas);
 }
diff --git a/src/format-readers/index.js b/src/format-readers/index.js
new file mode 100644
index 0000000..eeb157b
--- /dev/null
+++ b/src/format-readers/index.js
@@ -0,0 +1,15 @@
+import { dstRead } from "./dst";
+import { expRead } from "./exp";
+import { jefRead } from "./jef";
+import { pecRead } from "./pec";
+import { pesRead } from "./pes";
+
+const supportedFormats = {
+  pes: { ext: ".pes", read: pesRead },
+  dst: { ext: ".dst", read: dstRead },
+  pec: { ext: ".pec", read: pecRead },
+  jef: { ext: ".jef", read: jefRead },
+  exp: { ext: ".exp", read: expRead },
+};
+
+export { supportedFormats };
diff --git a/src/lib/FileViewer.svelte b/src/lib/FileViewer.svelte
index 514606b..41e7cb0 100644
--- a/src/lib/FileViewer.svelte
+++ b/src/lib/FileViewer.svelte
@@ -4,12 +4,13 @@
   import FileList from "./FileList.svelte";
 
   import { filterFiles } from "../utils/filterFiles";
+  import { supportedFormats } from "../format-readers";
 
   let acceptedFiles;
   let rejectedFiles;
   let areAcceptedFilesRendered = false;
   const fileRequirements = {
-    supportedFormats: [".pes", ".dst", ".pec", ".jef", ".exp"],
+    supportedFormats: Object.values(supportedFormats).map((f) => f.ext),
     maxSize: 700000,
   };