diff --git a/client/views/windows/connect.tpl b/client/views/windows/connect.tpl
index e50ebb5d..628c1764 100644
--- a/client/views/windows/connect.tpl
+++ b/client/views/windows/connect.tpl
@@ -29,13 +29,13 @@
 				<label for="connect:name">Name</label>
 			</div>
 			<div class="col-sm-9">
-				<input class="input" id="connect:name" name="name" value="{{defaults.name}}">
+				<input class="input" id="connect:name" name="name" value="{{defaults.name}}" maxlength="100">
 			</div>
 			<div class="col-sm-3">
 				<label for="connect:host">Server</label>
 			</div>
 			<div class="col-sm-6 col-xs-8">
-				<input class="input" id="connect:host" name="host" value="{{defaults.host}}" aria-label="Server address" required {{#if lockNetwork}}disabled{{/if}}>
+				<input class="input" id="connect:host" name="host" value="{{defaults.host}}" aria-label="Server address" maxlength="255" required {{#if lockNetwork}}disabled{{/if}}>
 			</div>
 			<div class="col-sm-3 col-xs-4">
 				<div class="port">
@@ -65,28 +65,28 @@
 			<label for="connect:nick">Nick</label>
 		</div>
 		<div class="col-sm-9">
-			<input class="input nick" id="connect:nick" name="nick" value="{{defaults.nick}}" required>
+			<input class="input nick" id="connect:nick" name="nick" value="{{defaults.nick}}" maxlength="100" required>
 		</div>
 	{{#unless useHexIp}}
 		<div class="col-sm-3">
 			<label for="connect:username">Username</label>
 		</div>
 		<div class="col-sm-9">
-			<input class="input username" id="connect:username" name="username" value="{{defaults.username}}">
+			<input class="input username" id="connect:username" name="username" value="{{defaults.username}}" maxlength="512">
 		</div>
 	{{/unless}}
 		<div class="col-sm-3">
 			<label for="connect:password">Password</label>
 		</div>
 		<div class="col-sm-9 password-container">
-			<input class="input" id="connect:password" type="password" name="password" value="{{defaults.password}}">
+			<input class="input" id="connect:password" type="password" name="password" value="{{defaults.password}}" maxlength="512">
 			{{> ../reveal-password}}
 		</div>
 		<div class="col-sm-3">
 			<label for="connect:realname">Real name</label>
 		</div>
 		<div class="col-sm-9">
-			<input class="input" id="connect:realname" name="realname" value="{{defaults.realname}}">
+			<input class="input" id="connect:realname" name="realname" value="{{defaults.realname}}" maxlength="512">
 		</div>
 	{{#if defaults.uuid}}
 		<div class="col-sm-3">
diff --git a/src/models/network.js b/src/models/network.js
index 0bf59524..28edc340 100644
--- a/src/models/network.js
+++ b/src/models/network.js
@@ -64,6 +64,11 @@ function Network(attr) {
 }
 
 Network.prototype.validate = function(client) {
+	// If entered nick is over 100 characters, limit it so we don't try to compile a big regex
+	if (this.nick && this.nick.length > 100) {
+		this.nick = this.nick.substring(0, 100);
+	}
+
 	this.setNick(String(this.nick || Helper.getDefaultNick()).replace(" ", "_"));
 
 	if (!this.username) {
diff --git a/src/plugins/inputs/nick.js b/src/plugins/inputs/nick.js
index a0a486ed..ecff77ae 100644
--- a/src/plugins/inputs/nick.js
+++ b/src/plugins/inputs/nick.js
@@ -24,6 +24,14 @@ exports.input = function(network, chan, cmd, args) {
 
 	const newNick = args[0];
 
+	if (newNick.length > 100) {
+		chan.pushMessage(this, new Msg({
+			type: Msg.Type.ERROR,
+			text: "Nicknames may not be this long.",
+		}));
+		return;
+	}
+
 	// If connected to IRC, send to server and wait for ACK
 	// otherwise update the nick and UI straight away
 	if (network.irc && network.irc.connection) {