diff --git a/ui/src/components/community-form.tsx b/ui/src/components/community-form.tsx
index 0613ef4d2..14c2a6b8c 100644
--- a/ui/src/components/community-form.tsx
+++ b/ui/src/components/community-form.tsx
@@ -76,13 +76,13 @@ export class CommunityForm extends Component<CommunityFormProps, CommunityFormSt
         <div class="form-group row">
           <label class="col-12 col-form-label">Name</label>
           <div class="col-12">
-            <input type="text" class="form-control" value={this.state.communityForm.name} onInput={linkEvent(this, this.handleCommunityNameChange)} required minLength={3} pattern="[a-z0-9_]+" title="lowercase, underscores, and no spaces."/>
+            <input type="text" class="form-control" value={this.state.communityForm.name} onInput={linkEvent(this, this.handleCommunityNameChange)} required minLength={3} maxLength={20} pattern="[a-z0-9_]+" title="lowercase, underscores, and no spaces."/>
           </div>
         </div>
         <div class="form-group row">
           <label class="col-12 col-form-label">Title</label>
           <div class="col-12">
-            <input type="text" value={this.state.communityForm.title} onInput={linkEvent(this, this.handleCommunityTitleChange)} class="form-control" required minLength={3} />
+            <input type="text" value={this.state.communityForm.title} onInput={linkEvent(this, this.handleCommunityTitleChange)} class="form-control" required minLength={3} maxLength={100} />
           </div>
         </div>
         <div class="form-group row">
diff --git a/ui/src/components/login.tsx b/ui/src/components/login.tsx
index e871acef5..4d0b22d02 100644
--- a/ui/src/components/login.tsx
+++ b/ui/src/components/login.tsx
@@ -98,7 +98,7 @@ export class Login extends Component<any, State> {
         <div class="form-group row">
           <label class="col-sm-2 col-form-label">Username</label>
           <div class="col-sm-10">
-            <input type="text" class="form-control" value={this.state.registerForm.username} onInput={linkEvent(this, this.handleRegisterUsernameChange)} required minLength={3} pattern="[a-zA-Z0-9_]+" />
+            <input type="text" class="form-control" value={this.state.registerForm.username} onInput={linkEvent(this, this.handleRegisterUsernameChange)} required minLength={3} maxLength={20} pattern="[a-zA-Z0-9_]+" />
           </div>
         </div>
         <div class="form-group row">
diff --git a/ui/src/components/post-form.tsx b/ui/src/components/post-form.tsx
index b8ea359fd..4627ab48c 100644
--- a/ui/src/components/post-form.tsx
+++ b/ui/src/components/post-form.tsx
@@ -86,7 +86,7 @@ export class PostForm extends Component<PostFormProps, PostFormState> {
           <div class="form-group row">
             <label class="col-sm-2 col-form-label">Title</label>
             <div class="col-sm-10">
-              <textarea value={this.state.postForm.name} onInput={linkEvent(this, this.handlePostNameChange)} class="form-control" required rows={2} />
+              <textarea value={this.state.postForm.name} onInput={linkEvent(this, this.handlePostNameChange)} class="form-control" required rows={2} minLength={3} maxLength={100} />
             </div>
           </div>
           <div class="form-group row">
diff --git a/ui/src/components/setup.tsx b/ui/src/components/setup.tsx
index 94480ee82..9560a60dc 100644
--- a/ui/src/components/setup.tsx
+++ b/ui/src/components/setup.tsx
@@ -65,7 +65,7 @@ export class Setup extends Component<any, State> {
         <div class="form-group row">
           <label class="col-sm-2 col-form-label">Username</label>
           <div class="col-sm-10">
-            <input type="text" class="form-control" value={this.state.userForm.username} onInput={linkEvent(this, this.handleRegisterUsernameChange)} required minLength={3} pattern="[a-zA-Z0-9_]+" />
+            <input type="text" class="form-control" value={this.state.userForm.username} onInput={linkEvent(this, this.handleRegisterUsernameChange)} required minLength={3} maxLength={20} pattern="[a-zA-Z0-9_]+" />
           </div>
         </div>
         <div class="form-group row">
diff --git a/ui/src/components/site-form.tsx b/ui/src/components/site-form.tsx
index 78a332f61..7ca45b86e 100644
--- a/ui/src/components/site-form.tsx
+++ b/ui/src/components/site-form.tsx
@@ -37,7 +37,7 @@ export class SiteForm extends Component<SiteFormProps, SiteFormState> {
         <div class="form-group row">
           <label class="col-12 col-form-label">Name</label>
           <div class="col-12">
-            <input type="text" class="form-control" value={this.state.siteForm.name} onInput={linkEvent(this, this.handleSiteNameChange)} required minLength={3} />
+            <input type="text" class="form-control" value={this.state.siteForm.name} onInput={linkEvent(this, this.handleSiteNameChange)} required minLength={3} maxLength={20} />
           </div>
         </div>
         <div class="form-group row">