 <p>You just need to remove the padding from the button.</p> <p><a href="http://jsfiddle.net/fzuAh/1/" rel="nofollow">JSFiddle</a></p> <pre><code>input { padding:0; } </code></pre> <p>This is caused by the following style applied in the Chrome user agent stylesheet.</p> <pre><code>input[type="button"], input[type="submit"], input[type="reset"], input[type="file"]::-webkit-file-upload-button, button { padding: 1px 6px; } </code></pre>