diff --git a/src/components/UploadAvatarForm.tsx b/src/components/UploadAvatarForm.tsx
index 6746a5c..0cef7ef 100644
--- a/src/components/UploadAvatarForm.tsx
+++ b/src/components/UploadAvatarForm.tsx
@@ -1,4 +1,5 @@
 import type { Character } from "@src/db/characters"
+import { MAX_UPLOAD_SIZE } from "@src/db/uploads"
 import { ModalContent } from "./ui/ModalContent"
 
 export interface UploadAvatarFormProps {
@@ -6,59 +7,63 @@ export interface UploadAvatarFormProps {
   errors?: Record<string, string>
 }
 
-export const UploadAvatarForm = ({ character, errors }: UploadAvatarFormProps) => (
-  <ModalContent title="Upload Avatar">
-    <div class="modal-body" id="avatarUploadModalBody">
-      <div class="mb-3">
-        <label for="avatarFileInput" class="form-label">
-          Choose an image (max 10MB)
-        </label>
-        <input
-          class="form-control"
-          type="file"
-          id="avatarFileInput"
-          accept="image/jpeg,image/png,image/webp,image/gif"
-        />
-        <div class="form-text">Supported formats: JPEG, PNG, WebP, GIF</div>
-      </div>
+export function UploadAvatarForm({ character, errors }: UploadAvatarFormProps) {
+  const maxMb = Math.floor(MAX_UPLOAD_SIZE / (1024 * 1024))
+
+  return (
+    <ModalContent title="Upload Avatar">
+      <div class="modal-body" id="avatarUploadModalBody">
+        <div class="mb-3">
+          <label for="avatarFileInput" class="form-label">
+            Choose an image (max {maxMb}MB)
+          </label>
+          <input
+            class="form-control"
+            type="file"
+            id="avatarFileInput"
+            accept="image/jpeg,image/png,image/webp,image/gif,image/heif"
+          />
+          <div class="form-text">Supported formats: JPEG, PNG, WebP, GIF, HEIF</div>
+        </div>
 
-      <div id="uploadProgress" class="d-none">
-        <div class="progress mb-3">
-          <div
-            class="progress-bar progress-bar-striped progress-bar-animated"
-            role="progressbar"
-            style="width: 100%"
-          >
-            Uploading...
+        <div id="uploadProgress" class="d-none">
+          <div class="progress mb-3">
+            <div
+              class="progress-bar progress-bar-striped progress-bar-animated"
+              role="progressbar"
+              style="width: 100%"
+            >
+              Uploading...
+            </div>
           </div>
         </div>
-      </div>
 
-      {/* Error alert - used for both client-side and server-side errors */}
-      <div
-        id="uploadError"
-        class={errors ? "alert alert-danger" : "alert alert-danger d-none"}
-        role="alert"
-      >
-        {errors && Object.values(errors).map((error) => <div>{error}</div>)}
-      </div>
+        {/* Error alert - used for both client-side and server-side errors */}
+        <div
+          id="uploadError"
+          class={errors ? "alert alert-danger" : "alert alert-danger d-none"}
+          role="alert"
+        >
+          {errors && Object.values(errors).map((error) => <div>{error}</div>)}
+        </div>
 
-      <div id="uploadSuccess" class="alert alert-success d-none" role="alert">
-        Avatar uploaded successfully!
+        <div id="uploadSuccess" class="alert alert-success d-none" role="alert">
+          Avatar uploaded successfully!
+        </div>
       </div>
-    </div>
-    <div class="modal-footer">
-      <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">
-        Cancel
-      </button>
-      <button
-        type="button"
-        class="btn btn-primary"
-        id="uploadAvatarBtn"
-        onclick={`handleAvatarUpload('${character.id}')`}
-      >
-        Upload
-      </button>
-    </div>
-  </ModalContent>
-)
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">
+          Cancel
+        </button>
+        <button
+          type="button"
+          class="btn btn-primary"
+          id="uploadAvatarBtn"
+          onclick={`handleAvatarUpload('${character.id}')`}
+        >
+          Upload
+        </button>
+      </div>
+    </ModalContent>
+  )
+}
diff --git a/src/db/uploads.ts b/src/db/uploads.ts
index 84a9365..e449b37 100644
--- a/src/db/uploads.ts
+++ b/src/db/uploads.ts
@@ -12,9 +12,15 @@ export const UploadStatus = {
 export type UploadStatusType = (typeof UploadStatus)[keyof typeof UploadStatus]
 
 // Allowed content types for uploads
-export const ALLOWED_IMAGE_TYPES = ["image/jpeg", "image/png", "image/webp", "image/gif"] as const
-
-export const MAX_UPLOAD_SIZE = 5 * 1024 * 1024 // 5MB
+export const ALLOWED_IMAGE_TYPES = [
+  "image/jpeg",
+  "image/png",
+  "image/webp",
+  "image/gif",
+  "image/heif",
+] as const
+
+export const MAX_UPLOAD_SIZE = 10 * 1024 * 1024 // 10MB
 
 // Zod schemas
 export const UploadSchema = z.object({
diff --git a/src/routes/uploads.test.ts b/src/routes/uploads.test.ts
index 13297e5..01cab10 100644
--- a/src/routes/uploads.test.ts
+++ b/src/routes/uploads.test.ts
@@ -1,6 +1,6 @@
 import { beforeEach, describe, expect, test } from "bun:test"
 import type { Upload } from "@src/db/uploads"
-import { UploadStatus } from "@src/db/uploads"
+import { MAX_UPLOAD_SIZE, UploadStatus } from "@src/db/uploads"
 import type { User } from "@src/db/users"
 import { useTestApp } from "@src/test/app"
 import { uploadFactory } from "@src/test/factories/upload"
@@ -55,7 +55,7 @@ describe("POST /uploads/initiate", () => {
       })
     })
 
-    describe("with invalid content type", () => {
+    describe("with unsupported type", () => {
       test("returns 400", async () => {
         const response = await makeRequest(testCtx.app, "/uploads/initiate", {
           user,
@@ -69,7 +69,7 @@ describe("POST /uploads/initiate", () => {
 
         expect(response.status).toBe(400)
         const data = await response.json()
-        expect(data.error).toContain("Invalid content type")
+        expect(data.error).toContain("Unsupported file type")
       })
     })
 
@@ -81,13 +81,13 @@ describe("POST /uploads/initiate", () => {
           headers: { "Content-Type": "application/json" },
           body: JSON.stringify({
             content_type: "image/jpeg",
-            size_bytes: 10 * 1024 * 1024, // 10MB
+            size_bytes: MAX_UPLOAD_SIZE + 10,
           }),
         })
 
         expect(response.status).toBe(400)
         const data = await response.json()
-        expect(data.error).toContain("Invalid file size")
+        expect(data.error).toContain("too big")
       })
     })
   })
diff --git a/src/services/uploads.ts b/src/services/uploads.ts
index a780459..dfdfa7c 100644
--- a/src/services/uploads.ts
+++ b/src/services/uploads.ts
@@ -28,14 +28,14 @@ export async function initiateUpload(
   // Validate content type
   if (!isValidContentType(contentType)) {
     throw new Error(
-      `Invalid content type: ${contentType}. Allowed types: ${uploads.ALLOWED_IMAGE_TYPES.join(", ")}`
+      `Unsupported file type '${contentType}'; allowed types: ${uploads.ALLOWED_IMAGE_TYPES.join(", ")}`
     )
   }
 
   // Validate size
   if (!isValidSize(sizeBytes)) {
     throw new Error(
-      `Invalid file size: ${sizeBytes} bytes. Maximum allowed: ${uploads.MAX_UPLOAD_SIZE} bytes`
+      `File size (${sizeBytes / (1024 * 1024)} MB) too big; max allowed: ${uploads.MAX_UPLOAD_SIZE / (1024 * 1024)} MB`
     )
   }
 
diff --git a/static/character.js b/static/character.js
index f53f52a..4a0d83c 100644
--- a/static/character.js
+++ b/static/character.js
@@ -63,21 +63,6 @@ async function handleAvatarUpload(characterId) {
     return;
   }
 
-  // Validate file type
-  const validTypes = ['image/jpeg', 'image/png', 'image/webp', 'image/gif'];
-  if (!validTypes.includes(file.type)) {
-    errorDiv.textContent = 'Invalid file type. Please select a JPEG, PNG, WebP, or GIF image.';
-    errorDiv.classList.remove('d-none');
-    return;
-  }
-
-  // Validate file size (5MB)
-  if (file.size > 10 * 1024 * 1024) {
-    errorDiv.textContent = 'File too large. Maximum size is 5MB.';
-    errorDiv.classList.remove('d-none');
-    return;
-  }
-
   // Hide error/success, show progress
   errorDiv.classList.add('d-none');
   successDiv.classList.add('d-none');