diff --git a/app/routes/api_auth.py b/app/routes/api_auth.py
index 554b86f..cf09df0 100644
--- a/app/routes/api_auth.py
+++ b/app/routes/api_auth.py
@@ -4,7 +4,9 @@
 
 from fastapi import APIRouter, Depends, HTTPException
 from fastapi.security import HTTPBearer
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, field_validator
+from sqlalchemy import func
+from sqlalchemy.exc import IntegrityError
 from sqlmodel import Session, select
 
 from app.auth.jwt import create_access_token
@@ -33,6 +35,20 @@ class AuthRequest(BaseModel):
     email: str = Field(min_length=1, max_length=254)
     password: str = Field(min_length=8)
 
+    @field_validator("email")
+    @classmethod
+    def _normalize_email(cls, v: str) -> str:
+        v = v.strip().lower()
+        local, _, domain = v.partition("@")
+        if not local or "." not in domain or " " in v:
+            raise ValueError("Enter a valid email address")
+        return v
+
+
+def _find_user_by_email(session: Session, email: str) -> User | None:
+    # Case-insensitive so accounts created before emails were normalized still match.
+    return session.exec(select(User).where(func.lower(User.email) == email)).first()
+
 
 class TokenPairResponse(BaseModel):
     access_token: str
@@ -50,12 +66,17 @@ class RefreshRequest(BaseModel):
 
 @router.post("/register", response_model=TokenPairResponse, status_code=201)
 def register(body: AuthRequest, session: Session = Depends(get_session)):
-    if session.exec(select(User).where(User.email == body.email)).first():
+    if _find_user_by_email(session, body.email):
         raise HTTPException(status_code=409, detail="Email already registered")
 
     user = User(email=body.email, password_hash=hash_password(body.password))
     session.add(user)
-    session.commit()
+    try:
+        session.commit()
+    except IntegrityError:
+        # Two simultaneous signups with the same email: unique index wins.
+        session.rollback()
+        raise HTTPException(status_code=409, detail="Email already registered") from None
     session.refresh(user)
     uid = user.id
     assert uid is not None
@@ -73,7 +94,7 @@ def register(body: AuthRequest, session: Session = Depends(get_session)):
 
 @router.post("/login", response_model=TokenPairResponse)
 def login(body: AuthRequest, session: Session = Depends(get_session)):
-    user = session.exec(select(User).where(User.email == body.email)).first()
+    user = _find_user_by_email(session, body.email)
     if not user or not verify_password(body.password, user.password_hash):
         raise HTTPException(status_code=401, detail="Invalid email or password")
 
diff --git a/frontend/src/api/client.ts b/frontend/src/api/client.ts
index 54698d4..3f7cd73 100644
--- a/frontend/src/api/client.ts
+++ b/frontend/src/api/client.ts
@@ -8,6 +8,22 @@ export class ApiError extends Error {
   }
 }
 
+// FastAPI returns `detail` as a string for HTTPException but as an array of
+// {loc, msg, ...} objects for 422 validation errors. Turn either into text.
+function formatDetail(detail: unknown, fallback: string): string {
+  if (typeof detail === 'string') return detail
+  if (Array.isArray(detail)) {
+    const msgs = detail
+      .map((d) => (d && typeof d === 'object' && 'msg' in d ? String((d as { msg: unknown }).msg) : ''))
+      .filter(Boolean)
+    if (msgs.length) return msgs.join('; ')
+  }
+  return fallback
+}
+
+const NETWORK_ERROR_MESSAGE =
+  "Can't reach the server. It may be waking up (free hosting) — please try again in a minute."
+
 async function apiFetchRaw<T>(path: string, options: RequestInit = {}): Promise<T> {
   const token = localStorage.getItem('access_token')
   const headers: Record<string, string> = {
@@ -15,10 +31,15 @@ async function apiFetchRaw<T>(path: string, options: RequestInit = {}): Promise<
     ...(options.headers as Record<string, string>),
   }
   if (token) headers['Authorization'] = `Bearer ${token}`
-  const res = await fetch(`${BASE}${path}`, { ...options, headers })
+  let res: Response
+  try {
+    res = await fetch(`${BASE}${path}`, { ...options, headers })
+  } catch {
+    throw new ApiError(0, NETWORK_ERROR_MESSAGE)
+  }
   if (!res.ok) {
     const body = await res.json().catch(() => ({ detail: res.statusText }))
-    throw new ApiError(res.status, body.detail ?? res.statusText)
+    throw new ApiError(res.status, formatDetail(body.detail, res.statusText || 'Request failed'))
   }
   if (res.status === 204) return undefined as unknown as T
   return res.json()
diff --git a/frontend/src/pages/Register.tsx b/frontend/src/pages/Register.tsx
index d4d426a..e324a29 100644
--- a/frontend/src/pages/Register.tsx
+++ b/frontend/src/pages/Register.tsx
@@ -21,7 +21,7 @@ export default function Register() {
       await register(fd.get('email') as string, fd.get('password') as string)
       navigate('/profile')
     } catch (err) {
-      setError(err instanceof ApiError ? err.message : 'Something went wrong')
+      setError(err instanceof ApiError ? err.message : 'Unexpected response from the server. Please try again.')
     } finally { setLoading(false) }
   }
 
@@ -33,14 +33,20 @@ export default function Register() {
         <h1 className="text-xl font-medium mb-4">Create account</h1>
         {error && <p className="text-sm text-red-600 bg-red-50 border border-red-200 rounded-lg px-3 py-2 mb-3">{error}</p>}
         <form onSubmit={handleSubmit} className="space-y-3">
-          <input name="email" type="email" placeholder="name@company.com" required
+          <input name="email" type="email" placeholder="name@company.com" required autoComplete="email"
             className="w-full border border-slate-300 rounded-lg px-3 py-3 text-base bg-white" />
-          <input name="password" type="password" placeholder="Password" required
+          <input name="password" type="password" placeholder="Password (min. 8 characters)" required
+            minLength={8} autoComplete="new-password"
             className="w-full border border-slate-300 rounded-lg px-3 py-3 text-base bg-white" />
           <button disabled={loading}
             className="w-full bg-slate-900 text-white rounded-lg px-4 py-3 text-base font-medium disabled:opacity-60">
             {loading ? 'Creating account…' : 'Register'}
           </button>
+          {loading && (
+            <p className="text-xs text-slate-500 text-center">
+              The server may be waking up — this can take up to a minute on first use.
+            </p>
+          )}
         </form>
         <p className="text-sm text-slate-600 mt-4 text-center">Have an account? <Link to="/login" className="underline">Log in</Link></p>
       </div>
diff --git a/tests/api/test_api.py b/tests/api/test_api.py
index 7313401..072045d 100644
--- a/tests/api/test_api.py
+++ b/tests/api/test_api.py
@@ -63,6 +63,46 @@ def test_duplicate_registration_conflicts(client):
     assert resp.status_code == 409
 
 
+def test_duplicate_registration_is_case_insensitive(client):
+    client.post(
+        "/api/auth/register",
+        json={"email": "Case@X.com", "password": "password123"},
+    )
+    resp = client.post(
+        "/api/auth/register",
+        json={"email": "  case@x.COM ", "password": "password456"},
+    )
+    assert resp.status_code == 409
+
+
+def test_login_email_is_case_insensitive(client):
+    client.post(
+        "/api/auth/register",
+        json={"email": "mixed@x.com", "password": "password123"},
+    )
+    resp = client.post(
+        "/api/auth/login",
+        json={"email": "MIXED@x.com", "password": "password123"},
+    )
+    assert resp.status_code == 200
+
+
+def test_register_rejects_invalid_email(client):
+    resp = client.post(
+        "/api/auth/register",
+        json={"email": "not-an-email", "password": "password123"},
+    )
+    assert resp.status_code == 422
+
+
+def test_register_rejects_short_password(client):
+    resp = client.post(
+        "/api/auth/register",
+        json={"email": "short@x.com", "password": "short"},
+    )
+    assert resp.status_code == 422
+
+
 def test_history_persists_after_assess(registered_client):
     registered_client.post(
         "/api/assess",