Summary  
This chapter explains how to use the EXISTS command in Redis to check whether single or multiple keys exist without retrieving their values, returning 1 for each existing key or a total count of existing keys.  

General domain of usage  
Caching systems

# EXISTS Command

If you simply need to **check** whether a **key** exists in **Redis** without **retrieving its value**, you can **use** the `EXISTS` **command**.

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    />
  </head>
  <body>
    <div class="text-widget">
      
      <input
        type="text"
        class="text-field"
        id="widget1-text"
        value="EXISTS [key1] [key2] ...
"
      />
      
      <button
        class="copy-button"
        onclick="handleClick('widget1-text', 'widget1-notify')"
      >
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              fill="#a6b8e6"
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## Example Usage

If you provide a **single key**, the **result** will be `1` if the **key exists**, or `0` if **it does not**.

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  <head>
    <meta charset="UTF-8" />
    <link
      rel="stylesheet"
      href="https://cdn.jsdelivr.net/npm/notiflix@2.7.0/dist/notiflix-aio-2.7.0.min.css"
    />
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    />
  </head>
  <body>
    <div class="text-widget">
      
      <input
        type="text"
        class="text-field"
        id="widget1-text"
        value="EXISTS mykey
"
      />
      
      <button
        class="copy-button"
        onclick="handleClick('widget1-text', 'widget1-notify')"
      >
        <svg width="20" height="20" viewBox="0 0 32 32" xml:space="preserve">
          <g>
            <path
              d="m26.121 6.707-3.828-3.828A2.98 2.98 0 0 0 20.172 2H12a3.003 3.003 0 0 0-3 3v1H8a3.003 3.003 0 0 0-3 3v18a3.003 3.003 0 0 0 3 3h12a3.003 3.003 0 0 0 3-3v-1h1a3.003 3.003 0 0 0 3-3V8.829a2.982 2.982 0 0 0-.879-2.122ZM22 5.414 23.586 7H22ZM20 28H8a1.001 1.001 0 0 1-1-1V9a1.001 1.001 0 0 1 1-1h8v3a2.002 2.002 0 0 0 2 2h3v14a1 1 0 0 1-1 1ZM18 9.414 19.586 11H18ZM24 24h-1V12.829a2.982 2.982 0 0 0-.879-2.122l-3.828-3.828A2.98 2.98 0 0 0 16.171 6H11V5a1.001 1.001 0 0 1 1-1h8v3a2.002 2.002 0 0 0 2 2h3v14a1 1 0 0 1-1 1Zm-6-8h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Zm0 4h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Zm0 4h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Z"
              fill="#a6b8e6"
            ></path>
          </g>
        </svg>
      </button>
    </div>
    
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In this case, the **result** will be `1` since the **key** `mykey` **exists**.

When **multiple keys** are specified, the **command** will return the **number of keys that exist** in Redis. If we also have **keys** `key1` and `key3` in the **database**, this query will **return** `2`, since only `key1` and `key3` **exist** in the **database**.

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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <link
      rel="stylesheet"
      href="https://cdn.jsdelivr.net/npm/notiflix@2.7.0/dist/notiflix-aio-2.7.0.min.css"
    />
    <link
      rel="stylesheet"
      href="https://content-media-cdn.codefinity.com/courses/c1087363-9025-4c37-8d5e-983a32a007e9/text-boxes-section/copyable-text-box.css"
    />
  </head>
  <body>
    <div class="text-widget">
      
      <input
        type="text"
        class="text-field"
        id="widget1-text"
        value="EXISTS key1 key2 key3
"
      />
      
      <button
        class="copy-button"
        onclick="handleClick('widget1-text', 'widget1-notify')"
      >
        <svg width="20" height="20" viewBox="0 0 32 32" xml:space="preserve">
          <g>
            <path
              d="m26.121 6.707-3.828-3.828A2.98 2.98 0 0 0 20.172 2H12a3.003 3.003 0 0 0-3 3v1H8a3.003 3.003 0 0 0-3 3v18a3.003 3.003 0 0 0 3 3h12a3.003 3.003 0 0 0 3-3v-1h1a3.003 3.003 0 0 0 3-3V8.829a2.982 2.982 0 0 0-.879-2.122ZM22 5.414 23.586 7H22ZM20 28H8a1.001 1.001 0 0 1-1-1V9a1.001 1.001 0 0 1 1-1h8v3a2.002 2.002 0 0 0 2 2h3v14a1 1 0 0 1-1 1ZM18 9.414 19.586 11H18ZM24 24h-1V12.829a2.982 2.982 0 0 0-.879-2.122l-3.828-3.828A2.98 2.98 0 0 0 16.171 6H11V5a1.001 1.001 0 0 1 1-1h8v3a2.002 2.002 0 0 0 2 2h3v14a1 1 0 0 1-1 1Zm-6-8h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Zm0 4h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Zm0 4h-8a1 1 0 0 1 0-2h8a1 1 0 0 1 0 2Z"
              fill="#a6b8e6"
            ></path>
          </g>
        </svg>
      </button>
    </div>
    
    <script src="https://cdn.jsdelivr.net/npm/notiflix@2.7.0/dist/notiflix-aio-2.7.0.min.js"></script>
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What will the EXISTS command return when checking multiple keys?

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