{ "schema_version": 2, "id": "commands/exists", "title": "EXISTS", "url": "https://redis.io/docs/latest/commands/exists/", "summary": "Determines whether one or more keys exist.", "since": "1.0.0", "tags": [ "docs", "develop", "stack", "oss", "rs", "rc", "oss", "kubernetes", "clients" ], "last_updated": "2026-09-18T09:48:32+01:00", "page_type": "content", "content_hash": "1601af7e80adfd115aeccb4cd20dc67ed6dd67f2b58b65151f7a14ec40135478", "sections": [ { "id": "required-arguments", "title": "Required arguments", "role": "content", "text": "
key [key ...]\n\nOne or more keys to check for existence. A repeated key is counted once per occurrence.\n\n
" }, { "id": "examples", "title": "Examples", "role": "example", "text": "Foundational: Check if one or more keys exist using EXISTS (returns count of existing keys, useful for conditional logic)\n\n**Difficulty:** Beginner\n\n**Commands:** SET, EXISTS\n\n**Complexity:**\n- SET: O(1)\n- EXISTS: O(N)\n\n**Available in:** Redis CLI, C, C#, Go, Java (Asynchronous - Lettuce), Java (Reactive - Lettuce), Java (Synchronous - Jedis), JavaScript (Node.js), JavaScript (Node.js), PHP, Python, Rust (Asynchronous), Rust (Synchronous)\n\n##### Redis CLI\n\n[code example]\n\n##### C\n\n[code example]\n\n##### C#\n\n[code example]\n\n##### Go\n\n[code example]\n\n##### Java (Asynchronous - Lettuce)\n\n[code example]\n\n##### Java (Reactive - Lettuce)\n\n[code example]\n\n##### Java (Synchronous - Jedis)\n\n[code example]\n\n##### JavaScript (Node.js)\n\n[code example]\n\n##### JavaScript (Node.js)\n\n[code example]\n\n##### JavaScript (Node.js)\n\n[code example]\n\n##### JavaScript (Node.js)\n\n[code example]\n\n##### PHP\n\n[code example]\n\n##### Python\n\n[code example]\n\n##### Rust (Asynchronous)\n\n[code example]\n\n##### Rust (Synchronous)\n\n[code example]" }, { "id": "redis-software-and-redis-cloud-compatibility", "title": "Redis Software and Redis Cloud compatibility", "role": "content", "text": "| Redis
Software | Redis
Cloud | Notes |\n|:----------------------|:-----------------|:------|\n| ✅ Standard
✅ Active-Active | ✅ Standard
✅ Active-Active | |" }, { "id": "return-information", "title": "Return information", "role": "returns", "text": "**RESP2:**\n\n[Integer reply](../../develop/reference/protocol-spec#integers): the number of keys that exist from those specified as arguments.\n\n**RESP3:**\n\n[Integer reply](../../develop/reference/protocol-spec#integers): the number of keys that exist from those specified as arguments." } ], "examples": [ { "id": "examples-ex0", "language": "plaintext", "code": "> SET key1 \"Hello\"\n> EXISTS key1\n> EXISTS nosuchkey\n> SET key2 \"World\"\n> EXISTS key1 key2 nosuchkey", "section_id": "examples" }, { "id": "examples-ex1", "language": "c", "code": "reply = redisCommand(c, \"SET key1 Hello\");\n printf(\"%s\\n\", reply->str);\n // >>> OK\n freeReplyObject(reply);\n\n reply = redisCommand(c, \"EXISTS key1\");\n printf(\"%lld\\n\", reply->integer);\n // >>> 1\n freeReplyObject(reply);\n\n reply = redisCommand(c, \"EXISTS nosuchkey\");\n printf(\"%lld\\n\", reply->integer);\n // >>> 0\n freeReplyObject(reply);\n\n reply = redisCommand(c, \"SET key2 World\");\n printf(\"%s\\n\", reply->str);\n // >>> OK\n freeReplyObject(reply);\n\n reply = redisCommand(c, \"EXISTS key1 key2 nosuchkey\");\n printf(\"%lld\\n\", reply->integer);\n // >>> 2\n freeReplyObject(reply);", "section_id": "examples" }, { "id": "examples-ex2", "language": "csharp", "code": "bool existsResult1 = db.StringSet(\"key1\", \"Hello\");\n Console.WriteLine(existsResult1); // >>> true\n\n bool existsResult2 = db.KeyExists(\"key1\");\n Console.WriteLine(existsResult2); // >>> true\n\n bool existsResult3 = db.KeyExists(\"nosuchkey\");\n Console.WriteLine(existsResult3); // >>> false\n\n bool existsResult4 = db.StringSet(\"key2\", \"World\");\n Console.WriteLine(existsResult4); // >>> true\n\n long existsResult5 = db.KeyExists([\"key1\", \"key2\", \"nosuchkey\"]);\n Console.WriteLine(existsResult5); // >>> 2", "section_id": "examples" }, { "id": "examples-ex3", "language": "go", "code": "existsResult1, err := rdb.Set(ctx, \"key1\", \"Hello\", 0).Result()\n\n\tif err != nil {\n\t\tpanic(err)\n\t}\n\n\tfmt.Println(existsResult1) // >>> OK\n\n\texistsResult2, err := rdb.Exists(ctx, \"key1\").Result()\n\n\tif err != nil {\n\t\tpanic(err)\n\t}\n\n\tfmt.Println(existsResult2) // >>> 1\n\n\texistsResult3, err := rdb.Exists(ctx, \"nosuchkey\").Result()\n\n\tif err != nil {\n\t\tpanic(err)\n\t}\n\n\tfmt.Println(existsResult3) // >>> 0\n\n\texistsResult4, err := rdb.Set(ctx, \"key2\", \"World\", 0).Result()\n\n\tif err != nil {\n\t\tpanic(err)\n\t}\n\n\tfmt.Println(existsResult4) // >>> OK\n\n\texistsResult5, err := rdb.Exists(ctx, \"key1\", \"key2\", \"nosuchkey\").Result()\n\n\tif err != nil {\n\t\tpanic(err)\n\t}\n\n\tfmt.Println(existsResult5) // >>> 2", "section_id": "examples" }, { "id": "examples-ex4", "language": "java", "code": "CompletableFuture existsExample = asyncCommands.set(\"key1\", \"Hello\").thenCompose(res1 -> {\n System.out.println(res1); // >>> OK\n\n return asyncCommands.exists(\"key1\");\n }).thenCompose(res2 -> {\n System.out.println(res2); // >>> 1\n\n return asyncCommands.exists(\"nosuchkey\");\n }).thenCompose(res3 -> {\n System.out.println(res3); // >>> 0\n\n return asyncCommands.set(\"key2\", \"World\");\n }).thenCompose(res4 -> {\n System.out.println(res4); // >>> OK\n\n return asyncCommands.exists(\"key1\", \"key2\", \"nosuchkey\");\n }).thenAccept(res5 -> {\n System.out.println(res5); // >>> 2\n }).toCompletableFuture();", "section_id": "examples" }, { "id": "examples-ex5", "language": "java", "code": "Mono existsExample = reactiveCommands.set(\"key1\", \"Hello\").doOnNext(res1 -> {\n System.out.println(res1); // >>> OK\n }).then(reactiveCommands.exists(\"key1\")).doOnNext(res2 -> {\n System.out.println(res2); // >>> 1\n }).then(reactiveCommands.exists(\"nosuchkey\")).doOnNext(res3 -> {\n System.out.println(res3); // >>> 0\n }).then(reactiveCommands.set(\"key2\", \"World\")).doOnNext(res4 -> {\n System.out.println(res4); // >>> OK\n }).then(reactiveCommands.exists(\"key1\", \"key2\", \"nosuchkey\")).doOnNext(res5 -> {\n System.out.println(res5); // >>> 2\n }).then();", "section_id": "examples" }, { "id": "examples-ex6", "language": "java", "code": "String existsResult1 = jedis.set(\"key1\", \"Hello\");\n System.out.println(existsResult1); // >>> OK\n\n boolean existsResult2 = jedis.exists(\"key1\");\n System.out.println(existsResult2); // >>> true\n\n boolean existsResult3 = jedis.exists(\"nosuchkey\");\n System.out.println(existsResult3); // >>> false\n\n String existsResult4 = jedis.set(\"key2\", \"World\");\n System.out.println(existsResult4); // >>> OK\n\n long existsResult5 = jedis.exists(\"key1\", \"key2\", \"nosuchkey\");\n System.out.println(existsResult5); // >>> 2", "section_id": "examples" }, { "id": "examples-ex7", "language": "javascript", "code": "const existsRes1 = await client.set('key1', 'Hello');\nconsole.log(existsRes1); // OK\n\nconst existsRes2 = await client.exists('key1');\nconsole.log(existsRes2); // 1\n\nconst existsRes3 = await client.exists('nosuchkey');\nconsole.log(existsRes3); // 0\n\nconst existsRes4 = await client.set('key2', 'World');\nconsole.log(existsRes4); // OK\n\nconst existsRes5 = await client.exists(['key1', 'key2', 'nosuchkey']);\nconsole.log(existsRes5); // 2", "section_id": "examples" }, { "id": "examples-ex8", "language": "javascript", "code": "console.log(await redis.set('key1', 'Hello')); // >>> OK\n\nconsole.log(await redis.exists('key1')); // >>> 1\nconsole.log(await redis.exists('nosuchkey')); // >>> 0\n\nconsole.log(await redis.set('key2', 'World')); // >>> OK\n\nconst existsResult = await redis.exists('key1', 'key2', 'nosuchkey');\nconsole.log(existsResult); // >>> 2", "section_id": "examples" }, { "id": "examples-ex9", "language": "javascript", "code": "const existsRes1 = await client.set('key1', 'Hello');\nconsole.log(existsRes1); // OK\n\nconst existsRes2 = await client.exists('key1');\nconsole.log(existsRes2); // 1\n\nconst existsRes3 = await client.exists('nosuchkey');\nconsole.log(existsRes3); // 0\n\nconst existsRes4 = await client.set('key2', 'World');\nconsole.log(existsRes4); // OK\n\nconst existsRes5 = await client.exists(['key1', 'key2', 'nosuchkey']);\nconsole.log(existsRes5); // 2", "section_id": "examples" }, { "id": "examples-ex10", "language": "javascript", "code": "console.log(await redis.set('key1', 'Hello')); // >>> OK\n\nconsole.log(await redis.exists('key1')); // >>> 1\nconsole.log(await redis.exists('nosuchkey')); // >>> 0\n\nconsole.log(await redis.set('key2', 'World')); // >>> OK\n\nconst existsResult = await redis.exists('key1', 'key2', 'nosuchkey');\nconsole.log(existsResult); // >>> 2", "section_id": "examples" }, { "id": "examples-ex11", "language": "php", "code": "$existsResult1 = $r->set('key1', 'Hello');\n echo $existsResult1 . PHP_EOL; // >>> OK\n\n $existsResult2 = $r->exists('key1');\n echo $existsResult2 . PHP_EOL; // >>> 1\n\n $existsResult3 = $r->exists('nosuchkey');\n echo $existsResult3 . PHP_EOL; // >>> 0\n\n $existsResult4 = $r->set('key2', 'World');\n echo $existsResult4 . PHP_EOL; // >>> OK\n\n $existsResult5 = $r->exists('key1', 'key2', 'nosuchkey');\n echo $existsResult5 . PHP_EOL; // >>> 2", "section_id": "examples" }, { "id": "examples-ex12", "language": "python", "code": "res = r.set(\"key1\", \"Hello\")\nprint(res)\n# >>> True\n\nres = r.exists(\"key1\")\nprint(res)\n# >>> 1\n\nres = r.exists(\"nosuchkey\")\nprint(res)\n# >>> 0\n\nres = r.set(\"key2\", \"World\")\nprint(res)\n# >>> True\n\nres = r.exists(\"key1\", \"key2\", \"nosuchkey\")\nprint(res)\n# >>> 2", "section_id": "examples" }, { "id": "examples-ex13", "language": "rust", "code": "if let Ok(res) = r.set(\"key1\", \"Hello\").await {\n let res: String = res;\n println!(\"{res}\"); // >>> OK\n }\n\n match r.exists(\"key1\").await {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 1\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }\n\n match r.exists(\"nosuchkey\").await {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 0\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }\n\n if let Ok(res) = r.set(\"key2\", \"World\").await {\n let res: String = res;\n println!(\"{res}\"); // >>> OK\n }\n\n match r.exists(&[\"key1\", \"key2\", \"nosuchkey\"]).await {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 2\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }", "section_id": "examples" }, { "id": "examples-ex14", "language": "rust", "code": "if let Ok(res) = r.set(\"key1\", \"Hello\") {\n let res: String = res;\n println!(\"{res}\"); // >>> OK\n }\n\n match r.exists(\"key1\") {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 1\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }\n\n match r.exists(\"nosuchkey\") {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 0\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }\n\n if let Ok(res) = r.set(\"key2\", \"World\") {\n let res: String = res;\n println!(\"{res}\"); // >>> OK\n }\n\n match r.exists(&[\"key1\", \"key2\", \"nosuchkey\"]) {\n Ok(res) => {\n let res: i32 = res;\n println!(\"{res}\"); // >>> 2\n },\n Err(e) => {\n println!(\"Error checking key existence: {e}\");\n return;\n }\n }", "section_id": "examples" } ] }