diff --git a/webserv/client/Client.cpp b/webserv/client/Client.cpp
index 9e69fed..b71633e 100644
--- a/webserv/client/Client.cpp
+++ b/webserv/client/Client.cpp
@@ -42,17 +42,19 @@ void Client::request()
     buffer[bytesRead] = '\0'; // NOLINT(cppcoreguidelines-pro-bounds-constant-array-index)
     httpRequest_->receiveData(buffer, static_cast<size_t>(bytesRead));
 
-    if (httpRequest_->getState() == HttpRequest::State::Complete)
+    if (httpRequest_->getState() == HttpRequest::State::Complete ||
+        httpRequest_->getState() == HttpRequest::State::ParseError)
     {
-        Log::info("Received complete request", {
-                                                   {"request_method", httpRequest_->getMethod()},
-                                                   {"request_target", httpRequest_->getTarget()},
-                                                   {"http_version", httpRequest_->getHttpVersion()},
-                                                   {"headers", httpRequest_->getHeaders().toString()},
-                                                   {"body", httpRequest_->getBody()},
-                                               });
+        Log::info("Received complete request",
+                  {
+                      {"request_method", httpRequest_->getMethod()},
+                      {"request_target", httpRequest_->getTarget()},
+                      {"http_version", httpRequest_->getHttpVersion()},
+                      {"headers", httpRequest_->getHeaders().toString()},
+                      {"body", httpRequest_->getBody()},
+                      {"state", std::to_string(static_cast<uint8_t>(httpRequest_->getState()))},
+                  });
         server_.responseReady(client_socket_->getFd());
-        httpRequest_->reset();
     }
     else
     {
@@ -66,8 +68,20 @@ void Client::request()
 
 std::string Client::getResponse() const
 {
-    std::string response = "HTTP/1.1 200 OK\r\nContent-Length: 32\r\n\r\nHello, World!";
-    response += " Server port " + std::to_string(server_config_.getPort()) + "\r\n";
+    Log::trace(LOCATION);
+    std::string response = "HTTP/1.1 ";
+    if (httpRequest_->getState() == HttpRequest::State::ParseError)
+    {
+        response += "400 Bad Request\r\n";
+    }
+    else
+    {
+        response += "200 OK\r\n";
+    }
+    // further validation can be added here
+    response += "Content-Length: 18\r\n\r\n";
+    response += "Server port " + std::to_string(server_config_.getPort()) + "\r\n";
+
     Log::debug("Sending response:\n" + response);
     return response;
 }
\ No newline at end of file
diff --git a/webserv/config/utils.cpp b/webserv/config/utils.cpp
index 98ee024..38ef03c 100644
--- a/webserv/config/utils.cpp
+++ b/webserv/config/utils.cpp
@@ -1,3 +1,4 @@
+
 #include <webserv/config/utils.hpp>
 
 #include <stdexcept>
@@ -7,11 +8,15 @@ namespace utils
 {
 size_t stoul(const std::string &str, int base)
 {
+    if (str.find_first_not_of("0123456789abcdefABCDEF") != std::string::npos)
+    {
+        throw std::invalid_argument("Invalid number: " + str);
+    }
     size_t idx = 0;
     unsigned long value = std::stoul(str, &idx, base);
     if (idx != str.length())
     {
-        throw std::invalid_argument("Invalid characters in number: " + str);
+        throw std::invalid_argument("Invalid number with extra characters: " + str);
     }
     return value;
 }
diff --git a/webserv/http/HttpHeaders.cpp b/webserv/http/HttpHeaders.cpp
index a85e070..28d1c52 100644
--- a/webserv/http/HttpHeaders.cpp
+++ b/webserv/http/HttpHeaders.cpp
@@ -16,20 +16,7 @@ std::optional<size_t> HttpHeaders::getContentLength() const
     {
         return std::nullopt;
     }
-    if (value.find_first_not_of("0123456789") != std::string::npos)
-    {
-        Log::warning("Non-numeric Content-Length header value: " + value);
-        return std::nullopt;
-    }
-    try
-    {
-        return utils::stoul(value);
-    }
-    catch (...)
-    {
-        Log::warning("Invalid Content-Length header value: " + value);
-        return std::nullopt;
-    }
+    return utils::stoul(value);
 }
 
 std::optional<std::string> HttpHeaders::getContentType() const
diff --git a/webserv/http/HttpRequest.cpp b/webserv/http/HttpRequest.cpp
index 1563f3e..c4eb869 100644
--- a/webserv/http/HttpRequest.cpp
+++ b/webserv/http/HttpRequest.cpp
@@ -1,3 +1,5 @@
+#include "webserv/config/utils.hpp"
+
 #include <webserv/http/HttpConstants.hpp> // for CRLF, DOUBLE_CRLF
 #include <webserv/http/HttpRequest.hpp>
 #include <webserv/log/Log.hpp> // for Log, LOCATION
@@ -47,36 +49,45 @@ void HttpRequest::parseBuffer()
 {
     while (true)
     {
-        switch (state_)
+        try
         {
-        case State::RequestLine:
-            if (!parseBufferforRequestLine())
+            switch (state_)
             {
-                return; // Wait for more data
+            case State::RequestLine:
+                if (!parseBufferforRequestLine())
+                {
+                    return; // Wait for more data
+                }
+                break;
+            case State::Headers:
+                if (!parseBufferforHeaders())
+                {
+                    return; // Wait for more data
+                }
+                break;
+            case State::Body:
+                if (!parseBufferforBody())
+                {
+                    return; // Wait for more data
+                }
+                break;
+            case State::Chunked:
+                if (!parseBufferforChunkedBody())
+                {
+                    return; // Wait for more data
+                }
+                break;
+            case State::Complete:
+                Log::debug("HttpRequest::parseBuffer() request is complete");
+                return; // Request is complete
+            case State::ParseError: Log::warning("Parse error occurred, stopping further processing"); return;
             }
-            break;
-        case State::Headers:
-            if (!parseBufferforHeaders())
-            {
-                return; // Wait for more data
-            }
-            break;
-        case State::Body:
-            if (!parseBufferforBody())
-            {
-                return; // Wait for more data
-            }
-            break;
-        case State::Chunked:
-            if (!parseBufferforChunkedBody())
-            {
-                return; // Wait for more data
-            }
-            break;
-        case State::Complete:
-            Log::debug("HttpRequest::parseBuffer() request is complete");
-            return; // Request is complete
-        case State::ParseError: Log::warning("Parse error occurred, stopping further processing"); return;
+        }
+        catch (...)
+        {
+            Log::error("Exception during parsing, marking request as ParseError");
+            state_ = State::ParseError;
+            return;
         }
     }
 }
@@ -124,10 +135,8 @@ bool HttpRequest::parseBufferforHeaders()
         Log::debug("Headers waiting for more data: " + LOCATION);
         return false; // Wait for more data
     }
-    // headers_ = buffer_.substr(0, pos + Http::Protocol::CRLF.size()); // Include the last \r\n
     headers_.parse(buffer_.substr(0, pos + Http::Protocol::CRLF.size()));
     buffer_.erase(0, pos + Http::Protocol::DOUBLE_CRLF.size());
-    // parseContentLength();
 
     if (this->headers_.getContentLength().value_or(0) > 0)
     {
@@ -156,17 +165,9 @@ bool HttpRequest::parseBufferforChunkedBody()
             return false;
         }
         std::string chunkSizeStr = buffer_.substr(0, pos);
-        size_t chunkSize = 0;
-        try
-        {
-            chunkSize = std::stoul(chunkSizeStr, nullptr, 16);
-        }
-        catch (const std::exception &e)
-        {
-            Log::warning("Invalid chunk size: " + chunkSizeStr + " (" + e.what() + ")");
-            state_ = State::ParseError; // Mark as complete to avoid further processing
-            return true;
-        }
+        Log::debug("Chunk size string: " + chunkSizeStr);
+        size_t chunkSize = utils::stoul(chunkSizeStr, 16);
+        Log::warning("Invalid chunk size: " + chunkSizeStr);
         if (chunkSize == 0)
         {
             state_ = State::Complete; // Last chunk