diff --git a/src/fr/devinsy/statoolinfos/checker/PropertyChecker.java b/src/fr/devinsy/statoolinfos/checker/PropertyChecker.java
index a0e5653..0d474d1 100644
--- a/src/fr/devinsy/statoolinfos/checker/PropertyChecker.java
+++ b/src/fr/devinsy/statoolinfos/checker/PropertyChecker.java
@@ -293,12 +293,12 @@ public class PropertyChecker
                 check = new PropertyCheck(lineIndex, "", Status.OK);
                 check.setComment("OK");
             }
-            else if ((StringUtils.isEmpty(line)) || (line.matches(COMMENT)))
+            else if ((StringUtils.isEmpty(line)) || (isComment(line)))
             {
                 check = new PropertyCheck(lineIndex, line, Status.OK);
                 check.setComment("OK");
             }
-            else if (!line.matches("^[^#].*[^\\s].*=.*$"))
+            else if (!isProperty(line))
             {
                 check = new PropertyCheck(lineIndex, line, Status.ERROR);
                 check.setComment("Ligne malformée");
@@ -458,4 +458,83 @@ public class PropertyChecker
         //
         return result;
     }
+
+    /**
+     * Checks if is comment.
+     *
+     * @param line
+     *            the line
+     * @return true, if is comment
+     */
+    public static boolean isComment(final String line)
+    {
+        boolean result;
+
+        // Method 1
+        // public static final Pattern COMMENT_PATTERN =
+        // Pattern.compile(COMMENT);
+        // result = COMMENT_PATTERN.matcher(line).matches();
+
+        // Method 2
+        // result = StringUtils.startsWith(line, "#");
+
+        // Method 3
+        if ((line != null) && (line.length() > 0) && (line.charAt(0) == '#'))
+        {
+            result = true;
+        }
+        else
+        {
+            result = false;
+        }
+
+        //
+        return result;
+    }
+
+    /**
+     * Checks if is property.
+     *
+     * @param line
+     *            the line
+     * @return true, if is property
+     */
+    public static boolean isProperty(final String line)
+    {
+        boolean result;
+
+        // Method 1, take so much time, > 1000 ms for each property file.
+        // public static final Pattern PROPERTY_PATTERN =
+        // Pattern.compile("^[^#].*[^\\s].*=.*$");
+        // result = PROPERTY_PATTERN.matcher(line).matches();
+
+        // Method 2, well optimized, < 1 ms for each property file.
+        if ((line == null) || (line.length() == 0))
+        {
+            result = false;
+        }
+        else
+        {
+            int splitter = line.indexOf('=');
+            if (splitter == -1)
+            {
+                result = false;
+            }
+            else
+            {
+                String path = line.substring(0, splitter);
+                if ((path.length() == 0) || (path.charAt(0) == '#') || (StringUtils.isBlank(path)))
+                {
+                    result = false;
+                }
+                else
+                {
+                    result = true;
+                }
+            }
+        }
+
+        //
+        return result;
+    }
 }
\ No newline at end of file
diff --git a/test/fr/devinsy/statoolinfos/checker/PropertyCheckerTest.java b/test/fr/devinsy/statoolinfos/checker/PropertyCheckerTest.java
new file mode 100644
index 0000000..5e53389
--- /dev/null
+++ b/test/fr/devinsy/statoolinfos/checker/PropertyCheckerTest.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2024 Christian Pierre MOMON <christian@momon.org>
+ * 
+ * This file is part of StatoolInfos, simple key value database.
+ * 
+ * StatoolInfos is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ * 
+ * StatoolInfos is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with StatoolInfos.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package fr.devinsy.statoolinfos.checker;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.config.Configurator;
+import org.apache.logging.log4j.core.config.DefaultConfiguration;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import fr.devinsy.statoolinfos.core.StatoolInfosException;
+
+/**
+ * The Class PropertyCheckerTest.
+ */
+public class PropertyCheckerTest
+{
+    private static org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(PropertyCheckerTest.class);
+
+    /**
+     *
+     */
+    @Test
+    public void PropertyCheckerIsCommentTest01()
+    {
+        Assert.assertFalse(PropertyChecker.isComment(null));
+        Assert.assertFalse(PropertyChecker.isComment(""));
+        Assert.assertFalse(PropertyChecker.isComment("    "));
+        Assert.assertFalse(PropertyChecker.isComment("foo"));
+        Assert.assertFalse(PropertyChecker.isComment("   foo   "));
+
+        Assert.assertTrue(PropertyChecker.isComment("#"));
+        Assert.assertTrue(PropertyChecker.isComment("# "));
+        Assert.assertTrue(PropertyChecker.isComment("# foo"));
+    }
+
+    /**
+    *
+    */
+    @Test
+    public void PropertyCheckerIsPropertyTest01()
+    {
+        Assert.assertFalse(PropertyChecker.isProperty(null));
+        Assert.assertFalse(PropertyChecker.isProperty(""));
+        Assert.assertFalse(PropertyChecker.isProperty("    "));
+        Assert.assertFalse(PropertyChecker.isProperty("   foo   "));
+        Assert.assertFalse(PropertyChecker.isProperty("foo"));
+        Assert.assertFalse(PropertyChecker.isProperty("#"));
+        Assert.assertFalse(PropertyChecker.isProperty("# "));
+        Assert.assertFalse(PropertyChecker.isProperty("# foo"));
+        Assert.assertFalse(PropertyChecker.isProperty("#foo=bar"));
+
+        Assert.assertTrue(PropertyChecker.isProperty("foo="));
+        Assert.assertTrue(PropertyChecker.isProperty("foo=    "));
+        Assert.assertTrue(PropertyChecker.isProperty("foo=bar"));
+        Assert.assertTrue(PropertyChecker.isProperty("foo=bar   "));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo="));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo=   "));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo=bar"));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo=bar   "));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo   =   bar"));
+        Assert.assertTrue(PropertyChecker.isProperty("   foo   =   bar   "));
+    }
+
+    /**
+     * After class.
+     * 
+     * @throws StatoolInfosException
+     *             the Juga exception
+     */
+    @AfterClass
+    public static void afterClass() throws StatoolInfosException
+    {
+    }
+
+    /**
+     * Before class.
+     * 
+     * @throws StatoolInfosException
+     *             the Juga exception
+     */
+    @BeforeClass
+    public static void beforeClass() throws StatoolInfosException
+    {
+        Configurator.initialize(new DefaultConfiguration());
+        Configurator.setRootLevel(Level.DEBUG);
+    }
+}