diff --git a/components/app.js b/components/app.js
index 83466c1..ff61830 100644
--- a/components/app.js
+++ b/components/app.js
@@ -5,8 +5,10 @@ import BufferList from "./buffer-list.js";
 import BufferHeader from "./buffer-header.js";
 import MemberList from "./member-list.js";
 import Connect from "./connect.js";
+import Join from "./join.js";
 import Composer from "./composer.js";
 import ScrollManager from "./scroll-manager.js";
+import Dialog from "./dialog.js";
 import { html, Component, createRef } from "../lib/index.js";
 import { strip as stripANSI } from "../lib/ansi.js";
 import { SERVER_BUFFER, BufferType, ReceiptType, NetworkStatus, Unread } from "../state.js";
@@ -151,6 +153,7 @@ export default class App extends Component {
 		networks: new Map(),
 		buffers: new Map(),
 		activeBuffer: null,
+		dialog: null,
 		error: null,
 	};
 	clients = new Map();
@@ -165,11 +168,13 @@ export default class App extends Component {
 		super(props);
 
 		this.handleConnectSubmit = this.handleConnectSubmit.bind(this);
+		this.handleJoinSubmit = this.handleJoinSubmit.bind(this);
 		this.handleBufferListClick = this.handleBufferListClick.bind(this);
 		this.handleComposerSubmit = this.handleComposerSubmit.bind(this);
 		this.handleNickClick = this.handleNickClick.bind(this);
 		this.autocomplete = this.autocomplete.bind(this);
 		this.handleBufferScrollTop = this.handleBufferScrollTop.bind(this);
+		this.handleDialogDismiss = this.handleDialogDismiss.bind(this);
 		this.dismissError = this.dismissError.bind(this);
 
 		this.saveReceipts = debounce(this.saveReceipts.bind(this), 500);
@@ -833,14 +838,15 @@ export default class App extends Component {
 	}
 
 	handleJoinClick(netID) {
-		var channel = prompt("Join channel:");
-		if (!channel) {
-			return;
-		}
+		this.setState({ dialog: "join", joinDialog: { network: netID } });
+	}
 
-		var client = this.clients.get(netID);
+	handleJoinSubmit(data) {
+		var client = this.clients.get(this.state.joinDialog.network);
 
-		client.send({ command: "JOIN", params: [channel] });
+		client.send({ command: "JOIN", params: [data.channel] });
+
+		this.setState({ dialog: null, joinDialog: null });
 	}
 
 	autocomplete(prefix) {
@@ -903,6 +909,10 @@ export default class App extends Component {
 		});
 	}
 
+	handleDialogDismiss() {
+		this.setState({ dialog: null });
+	}
+
 	componentDidMount() {
 		if (this.state.connectParams.autoconnect) {
 			this.connect(this.state.connectParams);
@@ -947,6 +957,17 @@ export default class App extends Component {
 			`;
 		}
 
+		var dialog = null;
+		switch (this.state.dialog) {
+		case "join":
+			dialog = html`
+				<${Dialog} title="Join channel" onDismiss=${this.handleDialogDismiss}>
+					<${Join} onSubmit=${this.handleJoinSubmit}/>
+				</>
+			`;
+			break;
+		}
+
 		var error = null;
 		if (this.state.error) {
 			error = html`
@@ -966,6 +987,7 @@ export default class App extends Component {
 			</>
 			${memberList}
 			<${Composer} ref=${this.composer} readOnly=${activeBuffer && activeBuffer.type == BufferType.SERVER} onSubmit=${this.handleComposerSubmit} autocomplete=${this.autocomplete}/>
+			${dialog}
 			${error}
 		`;
 	}
diff --git a/components/dialog.js b/components/dialog.js
new file mode 100644
index 0000000..3fccc15
--- /dev/null
+++ b/components/dialog.js
@@ -0,0 +1,61 @@
+import { html, Component, createRef } from "../lib/index.js";
+
+export default class Dialog extends Component {
+	body = createRef();
+
+	constructor(props) {
+		super(props);
+
+		this.handleCloseClick = this.handleCloseClick.bind(this);
+		this.handleBackdropClick = this.handleBackdropClick.bind(this);
+		this.handleKeyDown = this.handleKeyDown.bind(this);
+	}
+
+	dismiss() {
+		this.props.onDismiss();
+	}
+
+	handleCloseClick(event) {
+		event.preventDefault();
+		this.dismiss();
+	}
+
+	handleBackdropClick(event) {
+		if (event.target.className == "dialog") {
+			this.dismiss();
+		}
+	}
+
+	handleKeyDown(event) {
+		if (event.key == "Escape") {
+			this.dismiss();
+		}
+	}
+
+	componentDidMount() {
+		window.addEventListener("keydown", this.handleKeyDown);
+
+		var autofocus = this.body.current.querySelector("input[autofocus]");
+		if (autofocus) {
+			autofocus.focus();
+		}
+	}
+
+	componentWillUnmount() {
+		window.removeEventListener("keydown", this.handleKeyDown);
+	}
+
+	render() {
+		return html`
+			<div class="dialog" onClick=${this.handleBackdropClick}>
+				<div class="dialog-body" ref=${this.body}>
+					<div class="dialog-header">
+						<a href="#" class="dialog-close" onClick=${this.handleCloseClick}>×</span>
+						<h2>${this.props.title}</h2>
+					</div>
+					${this.props.children}
+				</div>
+			</div>
+		`;
+	}
+}
diff --git a/components/join.js b/components/join.js
new file mode 100644
index 0000000..81e4aa9
--- /dev/null
+++ b/components/join.js
@@ -0,0 +1,45 @@
+import { html, Component } from "../lib/index.js";
+
+export default class Join extends Component {
+	state = {
+		channel: "#",
+	};
+
+	constructor(props) {
+		super(props);
+
+		this.handleChange = this.handleChange.bind(this);
+		this.handleSubmit = this.handleSubmit.bind(this);
+	}
+
+	handleChange(event) {
+		var target = event.target;
+		var value = target.type == "checkbox" ? target.checked : target.value;
+		this.setState({ [target.name]: value });
+	}
+
+	handleSubmit(event) {
+		event.preventDefault();
+
+		var params = {
+			channel: this.state.channel,
+		};
+
+		this.props.onSubmit(params);
+	}
+
+	render() {
+		return html`
+			<form onChange=${this.handleChange} onSubmit=${this.handleSubmit}>
+				<label>
+					Channel:<br/>
+					<input type="text" name="channel" value=${this.state.channel} autofocus required/>
+				</label>
+				<br/>
+
+				<br/>
+				<button>Join</button>
+			</form>
+		`;
+	}
+}
diff --git a/style.css b/style.css
index 68866ad..ccadd02 100644
--- a/style.css
+++ b/style.css
@@ -136,10 +136,11 @@ body {
 	margin: 0 auto;
 	max-width: 300px;
 }
-#connect input[type="text"],
-#connect input[type="username"],
-#connect input[type="password"],
-#connect input[type="url"] {
+
+form input[type="text"],
+form input[type="username"],
+form input[type="password"],
+form input[type="url"] {
 	box-sizing: border-box;
 	width: 100%;
 }
@@ -274,3 +275,29 @@ details summary {
 .error-text {
 	color: red;
 }
+
+.dialog {
+	position: fixed;
+	top: 0;
+	left: 0;
+	right: 0;
+	bottom: 0;
+	background-color: rgba(0, 0, 0, 0.5);
+}
+.dialog .dialog-body {
+	background-color: white;
+	margin: auto;
+	margin-top: 20px;
+	max-width: 500px;
+	padding: 15px;
+	border: 1px solid rgba(0, 0, 0, 0.6);
+}
+.dialog a.dialog-close {
+	float: right;
+	text-decoration: none;
+	font-size: 1.5em;
+	color: inherit;
+}
+.dialog h2 {
+	margin-top: 0;
+}