diff --git a/packages/bruno-app/src/utils/codemirror/autocomplete.js b/packages/bruno-app/src/utils/codemirror/autocomplete.js
index 9e9dc5d6e..93ad76493 100644
--- a/packages/bruno-app/src/utils/codemirror/autocomplete.js
+++ b/packages/bruno-app/src/utils/codemirror/autocomplete.js
@@ -43,7 +43,11 @@ const STATIC_API_HINTS = {
     'res.getHeaders()',
     'res.getBody()',
     'res.setBody(data)',
-    'res.getResponseTime()'
+    'res.getResponseTime()',
+    'res.getSize()',
+    'res.getSize().header',
+    'res.getSize().body',
+    'res.getSize().total',
   ],
   bru: [
     'bru',
diff --git a/packages/bruno-cli/src/runner/run-single-request.js b/packages/bruno-cli/src/runner/run-single-request.js
index a7a0c3ca3..49ff39b20 100644
--- a/packages/bruno-cli/src/runner/run-single-request.js
+++ b/packages/bruno-cli/src/runner/run-single-request.js
@@ -415,8 +415,9 @@ const runSingleRequest = async function (
       /** @type {import('axios').AxiosResponse} */
       response = await axiosInstance(request);
 
-      const { data } = parseDataFromResponse(response, request.__brunoDisableParsingResponseJson);
+      const { data, dataBuffer } = parseDataFromResponse(response, request.__brunoDisableParsingResponseJson);
       response.data = data;
+      response.dataBuffer = dataBuffer;
 
       // Prevents the duration on leaking to the actual result
       responseTime = response.headers.get('request-duration');
@@ -428,8 +429,9 @@ const runSingleRequest = async function (
       }
     } catch (err) {
       if (err?.response) {
-        const { data } = parseDataFromResponse(err?.response);
+        const { data, dataBuffer } = parseDataFromResponse(err?.response);
         err.response.data = data;
+        err.response.dataBuffer = dataBuffer;
         response = err.response;
 
         // Prevents the duration on leaking to the actual result
diff --git a/packages/bruno-converters/src/postman/postman-translations.js b/packages/bruno-converters/src/postman/postman-translations.js
index 252c4c2d3..9dc48a5cd 100644
--- a/packages/bruno-converters/src/postman/postman-translations.js
+++ b/packages/bruno-converters/src/postman/postman-translations.js
@@ -26,6 +26,11 @@ const replacements = {
   'pm\\.response\\.headers\\.get\\(': 'res.getHeader(',
   'pm\\.response\\.to\\.have\\.body\\(': 'expect(res.getBody()).to.equal(',
   'pm\\.response\\.to\\.have\\.header\\(': 'expect(res.getHeaders()).to.have.property(',
+  'pm\\.response\\.size\\(\\)': 'res.getSize()',
+  'pm\\.response\\.size\\(\\)\\.body': 'res.getSize().body',
+  'pm\\.response\\.responseSize': 'res.getSize().body',
+  'pm\\.response\\.size\\(\\)\\.header': 'res.getSize().header',
+  'pm\\.response\\.size\\(\\)\\.total': 'res.getSize().total',
   'pm\\.environment\\.name': 'bru.getEnvName()',
   'pm\\.response\\.status': 'res.statusText',
   'pm\\.response\\.headers': 'res.getHeaders()',
diff --git a/packages/bruno-converters/src/utils/jscode-shift-translator.js b/packages/bruno-converters/src/utils/jscode-shift-translator.js
index 4d68c2b68..6b0cea683 100644
--- a/packages/bruno-converters/src/utils/jscode-shift-translator.js
+++ b/packages/bruno-converters/src/utils/jscode-shift-translator.js
@@ -84,6 +84,11 @@ const simpleTranslations = {
   'pm.response.responseTime': 'res.getResponseTime()',
   'pm.response.statusText': 'res.statusText',
   'pm.response.headers': 'res.getHeaders()',
+  'pm.response.size': 'res.getSize',
+  'pm.response.responseSize': 'res.getSize().body',
+  'pm.response.size().body': 'res.getSize().body',
+  'pm.response.size().header': 'res.getSize().header',
+  'pm.response.size().total': 'res.getSize().total',
   
   // Execution control
   'pm.execution.skipRequest': 'bru.runner.skipRequest',
diff --git a/packages/bruno-converters/tests/postman/postman-to-bruno/postman-translations/postman-response.spec.js b/packages/bruno-converters/tests/postman/postman-to-bruno/postman-translations/postman-response.spec.js
index a57b8435a..590825f13 100644
--- a/packages/bruno-converters/tests/postman/postman-to-bruno/postman-translations/postman-response.spec.js
+++ b/packages/bruno-converters/tests/postman/postman-to-bruno/postman-translations/postman-response.spec.js
@@ -9,6 +9,11 @@ describe('postmanTranslations - response commands', () => {
       const responseJson = pm.response.json();
       const responseStatus = pm.response.status;
       const responseHeaders = pm.response.headers;
+      const responseSize = pm.response.size();
+      const responseSizeBody = pm.response.size().body;
+      const responseSizeHeader = pm.response.size().header;
+      const responseSizeTotal = pm.response.size().total;
+      const responseSizeBody2 = pm.response.responseSize;
 
       pm.test('Status code is 200', function() {
         pm.response.to.have.status(200);
@@ -21,6 +26,11 @@ describe('postmanTranslations - response commands', () => {
       const responseJson = res.getBody();
       const responseStatus = res.statusText;
       const responseHeaders = res.getHeaders();
+      const responseSize = res.getSize();
+      const responseSizeBody = res.getSize().body;
+      const responseSizeHeader = res.getSize().header;
+      const responseSizeTotal = res.getSize().total;
+      const responseSizeBody2 = res.getSize().body;
 
       test('Status code is 200', function() {
         expect(res.getStatus()).to.equal(200);
@@ -29,6 +39,3 @@ describe('postmanTranslations - response commands', () => {
     expect(postmanTranslation(inputScript)).toBe(expectedOutput);
   });
 });
-
-
-
diff --git a/packages/bruno-converters/tests/postman/postman-translations/transpiler-tests/response.test.js b/packages/bruno-converters/tests/postman/postman-translations/transpiler-tests/response.test.js
index 3a1e45dbc..5df2fe5bb 100644
--- a/packages/bruno-converters/tests/postman/postman-translations/transpiler-tests/response.test.js
+++ b/packages/bruno-converters/tests/postman/postman-translations/transpiler-tests/response.test.js
@@ -553,4 +553,35 @@ describe('Response Translation', () => {
         expect(res.getBody()).to.equal({"status": "ok"});
         `);
     });
+
+    // --- getSize translations ---------------------------
+    it('should translate pm.response.size()', () => {
+        const code = 'const size = pm.response.size();';
+        const translatedCode = translateCode(code);
+        expect(translatedCode).toBe('const size = res.getSize();');
+    });
+
+    it('should translate pm.response.size().body', () => {
+        const code = 'const bodySize = pm.response.size().body;';
+        const translatedCode = translateCode(code);
+        expect(translatedCode).toBe('const bodySize = res.getSize().body;');
+    });
+
+    it('should translate pm.response.size().header', () => {
+        const code = 'const headerSize = pm.response.size().header;';
+        const translatedCode = translateCode(code);
+        expect(translatedCode).toBe('const headerSize = res.getSize().header;');
+    });
+
+    it('should translate pm.response.size().total', () => {
+        const code = 'const totalSize = pm.response.size().total;';
+        const translatedCode = translateCode(code);
+        expect(translatedCode).toBe('const totalSize = res.getSize().total;');
+    });
+
+    it('should translate pm.response.responseSize alias', () => {
+        const code = 'const responseSize = pm.response.responseSize;';
+        const translatedCode = translateCode(code);
+        expect(translatedCode).toBe('const responseSize = res.getSize().body;');
+    });
 }); 
\ No newline at end of file
diff --git a/packages/bruno-electron/src/ipc/network/index.js b/packages/bruno-electron/src/ipc/network/index.js
index dc45b86ec..21ae36d2b 100644
--- a/packages/bruno-electron/src/ipc/network/index.js
+++ b/packages/bruno-electron/src/ipc/network/index.js
@@ -876,8 +876,8 @@ const registerNetworkIpc = (mainWindow) => {
         statusText: response.statusText,
         headers: response.headers,
         data: response.data,
-        dataBuffer: dataBuffer.toString('base64'),
-        size: Buffer.byteLength(dataBuffer),
+        dataBuffer: response.dataBuffer.toString('base64'),
+        size: Buffer.byteLength(response.dataBuffer),
         duration: responseTime ?? 0,
         timeline: response.timeline
       };
@@ -1153,6 +1153,7 @@ const registerNetworkIpc = (mainWindow) => {
               response.data = data;
               response.dataBuffer = dataBuffer;
               response.responseTime = response.headers.get('request-duration');
+              response.headers.delete('request-duration');
 
               // save cookies
               if (preferencesUtil.shouldStoreCookies()) {
@@ -1174,8 +1175,8 @@ const registerNetworkIpc = (mainWindow) => {
                   dataBuffer: dataBuffer.toString('base64'),
                   size: Buffer.byteLength(dataBuffer),
                   data: response.data,
+                  responseTime: response.responseTime,
                   timeline: response.timeline,
-                  responseTime: response.headers.get('request-duration')
                 },
                 ...eventData
               });
@@ -1187,6 +1188,8 @@ const registerNetworkIpc = (mainWindow) => {
 
               if (error?.response) {
                 const { data, dataBuffer } = parseDataFromResponse(error.response);
+                error.response.responseTime = error.response.headers.get('request-duration');
+                error.response.headers.delete('request-duration');
                 error.response.data = data;
                 error.response.dataBuffer = dataBuffer;
 
@@ -1199,8 +1202,8 @@ const registerNetworkIpc = (mainWindow) => {
                   dataBuffer: dataBuffer.toString('base64'),
                   size: Buffer.byteLength(dataBuffer),
                   data: error.response.data,
+                  responseTime: error.response.responseTime,
                   timeline: error.response.timeline,
-                  responseTime: error.response.headers.get('request-duration')
                 };
 
                 // if we get a response from the server, we consider it as a success
diff --git a/packages/bruno-js/src/bruno-response.js b/packages/bruno-js/src/bruno-response.js
index dc78db285..1705d606f 100644
--- a/packages/bruno-js/src/bruno-response.js
+++ b/packages/bruno-js/src/bruno-response.js
@@ -52,6 +52,46 @@ class BrunoResponse {
     this.body = clonedData;
   }
 
+  // TODO: Refactor: dataBuffer size calculation should be handled in a shared utility so it can be passed and reused across the application
+  getSize() {
+    if (!this.res) {
+      return { header: 0, body: 0, total: 0 };
+    }
+
+    const { data, dataBuffer, headers } = this.res;
+    let bodySize = 0;
+    
+    // Use raw received bytes
+    if (Buffer.isBuffer(dataBuffer)) {
+      bodySize = dataBuffer.length;
+    } else {
+      // Use server-reported Content-Length
+      const contentLength = headers && (headers['content-length'] || headers['Content-Length']);
+      if (contentLength && !isNaN(contentLength)) {
+        bodySize = parseInt(contentLength, 10);
+      } else if (data != null) {
+        // Manual calculation
+        const raw = typeof data === 'string' ? data : JSON.stringify(data);
+        bodySize = Buffer.byteLength(raw);
+      }
+    }
+
+    const headerLines = [
+      `HTTP/1.1 ${this.res.status} ${this.res.statusText}`,
+      ...Object.entries(this.res.headers || {}).flatMap(([key, value]) =>
+        Array.isArray(value)
+          ? value.map((v) => `${key}: ${v}`)
+          : [`${key}: ${value}`]
+      ),
+      '',
+      ''
+    ];
+    const headerSize = Buffer.byteLength(headerLines.join('\r\n'));
+
+    return { header: headerSize, body: bodySize, total: headerSize + bodySize };
+    
+  }
+
   getDataBuffer() {
     return this.res ? this.res.dataBuffer : null;
   }
diff --git a/packages/bruno-js/src/sandbox/quickjs/shims/bruno-response.js b/packages/bruno-js/src/sandbox/quickjs/shims/bruno-response.js
index 6b9501876..50aca92ac 100644
--- a/packages/bruno-js/src/sandbox/quickjs/shims/bruno-response.js
+++ b/packages/bruno-js/src/sandbox/quickjs/shims/bruno-response.js
@@ -65,6 +65,12 @@ const addBrunoResponseShimToContext = (vm, res) => {
   vm.setProp(resFn, 'setBody', setBody);
   setBody.dispose();
 
+  let getSize = vm.newFunction('getSize', function () {
+    return marshallToVm(res.getSize(), vm);
+  });
+  vm.setProp(resFn, 'getSize', getSize);
+  getSize.dispose();
+
   vm.setProp(vm.global, 'res', resFn);
   resFn.dispose();
 };
diff --git a/packages/bruno-tests/collection/scripting/api/res/getSize.bru b/packages/bruno-tests/collection/scripting/api/res/getSize.bru
new file mode 100644
index 000000000..2d727ea07
--- /dev/null
+++ b/packages/bruno-tests/collection/scripting/api/res/getSize.bru
@@ -0,0 +1,36 @@
+meta {
+  name: getSize
+  type: http
+  seq: 8
+}
+
+get {
+  url: https://www.httpfaker.org/api/random/json?size=1mb
+  body: none
+  auth: inherit
+}
+
+params:query {
+  size: 1mb
+}
+
+script:post-response {
+  console.log(res.getSize())
+}
+
+tests {
+  test("test body size", function() {
+    const bodySize = res.getSize().body;
+    expect(bodySize === 1048934).to.be.true;
+  });
+  
+  test("test header size", function() {
+    const bodySize = res.getSize().header;
+    expect(bodySize === 305).to.be.true;
+  });
+  
+  test("test total size", function() {
+    const sizes = res.getSize();
+    expect(sizes.total).to.equal(sizes.header + sizes.body);
+  });
+}