diff --git a/play.pokemonshowdown.com/src/panel-chat.tsx b/play.pokemonshowdown.com/src/panel-chat.tsx
index da82cac50..aaba68340 100644
--- a/play.pokemonshowdown.com/src/panel-chat.tsx
+++ b/play.pokemonshowdown.com/src/panel-chat.tsx
@@ -824,6 +824,19 @@ export class CopyableURLBox extends preact.Component<{ url: string }> {
 	}
 }
 
+interface UserAutoCompleteCandidate {
+	type: "user";
+	userid: string;
+	prefixIndex: number;
+}
+
+interface CmdAutoCompleteCandidate {
+	type: "command";
+	command: string;
+}
+
+export type AutoCompleteCandidate = UserAutoCompleteCandidate | CmdAutoCompleteCandidate;
+
 export class ChatTextEntry extends preact.Component<{
 	room: ChatRoom, onMessage: (msg: string, elem: HTMLElement) => void, onKey: (e: KeyboardEvent) => boolean,
 	left?: number, tinyLayout?: boolean,
@@ -834,7 +847,7 @@ export class ChatTextEntry extends preact.Component<{
 	history: string[] = [];
 	historyIndex = 0;
 	tabComplete: {
-		candidates: { userid: string, prefixIndex: number }[],
+		candidates: AutoCompleteCandidate[],
 		candidateIndex: number,
 		/** the text left of the cursor before tab completing */
 		prefix: string,
@@ -1099,7 +1112,7 @@ export class ChatTextEntry extends preact.Component<{
 		return false;
 	}
 	// TODO - add support for commands tabcomplete
-	handleTabComplete(reverse: boolean) {
+	handleTabComplete(reverse: boolean): boolean {
 		// Don't tab complete at the start of the text box.
 		let { value, start, end } = this.getSelection();
 		if (start !== end || end === 0) return false;
@@ -1134,23 +1147,25 @@ export class ChatTextEntry extends preact.Component<{
 			const match2 = /^([\s\S!/]*?)([A-Za-z0-9][^, \n]* [^, ]*)$/.exec(prefix);
 			if (!match1 && !match2) return true;
 
+			const candidates: AutoCompleteCandidate[] = [];
 			const idprefix = (match1 ? toID(match1[2]) : '');
 			let spaceprefix = (match2 ? match2[2].replace(/[^A-Za-z0-9 ]+/g, '').toLowerCase() : '');
-			const candidates: { userid: string, prefixIndex: number }[] = [];
 			if (match2 && (match2[0] === '/' || match2[0] === '!')) spaceprefix = '';
 			for (const userid in users) {
 				if (spaceprefix && users[userid].slice(1).replace(/[^A-Za-z0-9 ]+/g, '')
 					.toLowerCase()
 					.startsWith(spaceprefix)) {
-					if (match2) candidates.push({ userid, prefixIndex: match2[1].length });
+					if (match2) candidates.push({ type: "user", userid, prefixIndex: match2[1].length });
 				} else if (idprefix && userid.startsWith(idprefix)) {
-					if (match1) candidates.push({ userid, prefixIndex: match1[1].length });
+					if (match1) candidates.push({ type: "user", userid, prefixIndex: match1[1].length });
 				}
 			}
 			// Sort by most recent to speak in the chat, or, in the case of a tie,
 			// in alphabetical order.
 			const userActivity = this.props.room.userActivity;
 			candidates.sort((a, b) => {
+				// command autocomplete options aren't added until after the user autocomplete options are sorted.
+				if (a.type !== "user" || b.type !== "user") return 0;
 				if (a.prefixIndex !== b.prefixIndex) {
 					// shorter prefix length comes first
 					return a.prefixIndex - b.prefixIndex;
@@ -1163,6 +1178,28 @@ export class ChatTextEntry extends preact.Component<{
 				return (a.userid < b.userid) ? -1 : 1; // alphabetical order
 			});
 
+			const currentLine = prefix.substring(prefix.lastIndexOf('\n') + 1);
+			const isCommandSearch = (currentLine.startsWith('/') && !currentLine.startsWith('//')) || currentLine.startsWith('!');
+			if (isCommandSearch) {
+				PS.mainmenu.makeQuery('cmdsearch', currentLine, true).then((data: string[]) => {
+					const cmds = data.sort((a, b) => a.length < b.length ? 1 : -1);
+					const nextCmd = cmds[cmds.length - 1];
+					const newValue = nextCmd + value.substring(end);
+					this.setValue(newValue, nextCmd.length, nextCmd.length);
+					const currentCandidates = this.tabComplete?.candidates ?? [];
+					for (const cmd of cmds) {
+						currentCandidates.unshift({ type: "command", command: cmd });
+					}
+					this.tabComplete = {
+						candidates: currentCandidates,
+						candidateIndex: 0,
+						prefix: nextCmd,
+						cursor: nextCmd,
+					};
+				});
+				return true;
+			}
+
 			if (!candidates.length) {
 				this.tabComplete = null;
 				return true;
@@ -1176,13 +1213,22 @@ export class ChatTextEntry extends preact.Component<{
 		}
 		// Substitute in the tab-completed name
 		const candidate = this.tabComplete.candidates[this.tabComplete.candidateIndex];
-		let name = users[candidate.userid];
-		if (!name) return true;
+		if (candidate.type === "user") {
+			let name = users[candidate.userid];
+			if (!name) return true;
 
-		name = Dex.getShortName(name.slice(1)); // Remove rank and busy characters
-		const cursor = this.tabComplete.prefix.slice(0, candidate.prefixIndex) + name;
-		this.setValue(cursor + value.slice(end), cursor.length);
-		this.tabComplete.cursor = cursor;
+			name = Dex.getShortName(name.slice(1)); // Remove rank and busy characters
+			const cursor = this.tabComplete.prefix.slice(0, candidate.prefixIndex) + name;
+			this.setValue(cursor + value.slice(end), cursor.length);
+			this.tabComplete.cursor = cursor;
+		} else {
+			const prefixIndex = prefix.lastIndexOf('\n') + 1;
+			const fullPrefix = prefix.substring(0, prefixIndex) + Dex.getShortName(candidate.command);
+			const newValue = fullPrefix + value.substring(end);
+			this.setValue(newValue, fullPrefix.length, fullPrefix.length);
+			this.tabComplete.cursor = fullPrefix;
+			this.tabComplete.prefix = fullPrefix;
+		}
 		return true;
 	}
 	undoTabComplete() {
diff --git a/play.pokemonshowdown.com/src/panel-mainmenu.tsx b/play.pokemonshowdown.com/src/panel-mainmenu.tsx
index 52a87e816..53f242f91 100644
--- a/play.pokemonshowdown.com/src/panel-mainmenu.tsx
+++ b/play.pokemonshowdown.com/src/panel-mainmenu.tsx
@@ -381,9 +381,9 @@ export class MainMenuRoom extends PSRoom {
 	 * Most queries are still handled hardcoded, so this is only for certain
 	 * special queries that need a Promise.
 	 */
-	makeQuery(id: string, param?: string) {
+	makeQuery(id: string, param?: string, excludeParamFromListener?: boolean) {
 		let fullid = id;
-		if (param) fullid += ` ${toID(param)}`;
+		if (param && !excludeParamFromListener) fullid += ` ${toID(param)}`;
 		return new Promise<any>(resolve => {
 			if (!this.listeners[fullid]) {
 				this.listeners[fullid] = [];