diff --git a/api/letters.js b/api/letters.js
index 433abfd6..80c5d5f7 100644
--- a/api/letters.js
+++ b/api/letters.js
@@ -34,6 +34,13 @@ export default async function handler(req, res) {
     }
   } else if (req.method === "POST") {
     const { text, signature, handle } = req.body
+
+    if (text.length > 100) {
+      res.statusCode = 400
+      res.end()
+      return
+    }
+
     try {
       const newLetter = await push(ref(database, "letters"))
       await set(newLetter, {
diff --git a/interface/sections/Letters.tsx b/interface/sections/Letters.tsx
index 0f188904..3fc672c2 100644
--- a/interface/sections/Letters.tsx
+++ b/interface/sections/Letters.tsx
@@ -293,6 +293,7 @@ function SendLetter(props: {
                   ? setLetterWritten(true)
                   : setLetterWritten(false)
               }}
+              maxLength={100}
               class="w-full h-full bg-zinc-100 px-4 py-3 resize-none rounded-xl transition-all outline-transparent focus:outline-4 focus:outline-zinc-500/10 focus:border-zinc-300 outline-offset-1 border border-zinc-200 dark:bg-zinc-800 dark:border-zinc-700 dark:placeholder:text-zinc-500 dark:focus:border-zinc-600 dark:focus:outline-none"
             ></textarea>
           </div>