diff --git a/docs/src/api/class-apirequestcontext.md b/docs/src/api/class-apirequestcontext.md
index 08cc8d993f..9275fb2d36 100644
--- a/docs/src/api/class-apirequestcontext.md
+++ b/docs/src/api/class-apirequestcontext.md
@@ -138,10 +138,13 @@ context cookies from the response. The method will automatically follow redirect
 ### param: APIRequestContext.delete.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.delete.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.delete.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.delete.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.delete.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.delete.params = %%-csharp-fetch-option-params-%%
@@ -297,10 +300,13 @@ await Request.FetchAsync("https://example.com/api/uploadScript", new() { Method
 
 Target URL or Request to get all parameters from.
 
+### option: APIRequestContext.fetch.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.fetch.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.fetch.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.fetch.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.fetch.params = %%-csharp-fetch-option-params-%%
@@ -397,10 +403,13 @@ await request.GetAsync("https://example.com/api/getText", new() { Params = query
 ### param: APIRequestContext.get.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.get.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.get.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.get.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.get.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.get.params = %%-csharp-fetch-option-params-%%
@@ -453,10 +462,13 @@ context cookies from the response. The method will automatically follow redirect
 ### param: APIRequestContext.head.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.head.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.head.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.head.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.head.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.head.params = %%-csharp-fetch-option-params-%%
@@ -509,10 +521,13 @@ context cookies from the response. The method will automatically follow redirect
 ### param: APIRequestContext.patch.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.patch.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.patch.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.patch.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.patch.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.patch.params = %%-csharp-fetch-option-params-%%
@@ -686,10 +701,13 @@ await request.PostAsync("https://example.com/api/uploadScript", new() { Multipar
 ### param: APIRequestContext.post.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.post.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.post.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.post.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.post.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.post.params = %%-csharp-fetch-option-params-%%
@@ -742,10 +760,13 @@ context cookies from the response. The method will automatically follow redirect
 ### param: APIRequestContext.put.url = %%-fetch-param-url-%%
 * since: v1.16
 
+### option: APIRequestContext.put.params = %%-js-fetch-option-params-%%
+* since: v1.16
+
 ### param: APIRequestContext.put.params = %%-java-csharp-fetch-params-%%
 * since: v1.18
 
-### option: APIRequestContext.put.params = %%-js-python-fetch-option-params-%%
+### option: APIRequestContext.put.params = %%-python-fetch-option-params-%%
 * since: v1.16
 
 ### option: APIRequestContext.put.params = %%-csharp-fetch-option-params-%%
diff --git a/docs/src/api/params.md b/docs/src/api/params.md
index 1743066647..f4adc23a3c 100644
--- a/docs/src/api/params.md
+++ b/docs/src/api/params.md
@@ -356,8 +356,14 @@ Emulates consistent window screen size available inside web page via `window.scr
 
 Target URL.
 
-## js-python-fetch-option-params
-* langs: js, python
+## js-fetch-option-params
+* langs: js
+- `params` <[Object]<[string], [string]|[number]|[boolean]>|[URLSearchParams]|[string]>
+
+Query parameters to be sent with the URL.
+
+## python-fetch-option-params
+* langs: python
 - `params` <[Object]<[string], [string]|[float]|[boolean]>>
 
 Query parameters to be sent with the URL.
diff --git a/packages/playwright-core/src/client/fetch.ts b/packages/playwright-core/src/client/fetch.ts
index 63f74ef26e..7aaa5069c2 100644
--- a/packages/playwright-core/src/client/fetch.ts
+++ b/packages/playwright-core/src/client/fetch.ts
@@ -32,7 +32,7 @@ import { TargetClosedError, isTargetClosedError } from './errors';
 import { toClientCertificatesProtocol } from './browserContext';
 
 export type FetchOptions = {
-  params?: { [key: string]: string; },
+  params?: { [key: string]: string | number | boolean; } | URLSearchParams | string,
   method?: string,
   headers?: Headers,
   data?: string | Buffer | Serializable,
@@ -175,7 +175,7 @@ export class APIRequestContext extends ChannelOwner<channels.APIRequestContextCh
       assert(options.maxRedirects === undefined || options.maxRedirects >= 0, `'maxRedirects' must be greater than or equal to '0'`);
       assert(options.maxRetries === undefined || options.maxRetries >= 0, `'maxRetries' must be greater than or equal to '0'`);
       const url = options.url !== undefined ? options.url : options.request!.url();
-      const params = objectToArray(options.params);
+      const params = mapParamsToArray(options.params);
       const method = options.method || options.request?.method();
       // Cannot call allHeaders() here as the request may be paused inside route handler.
       const headersObj = options.headers || options.request?.headers();
@@ -407,6 +407,30 @@ function objectToArray(map?: { [key: string]: any }): NameValue[] | undefined {
   return result;
 }
 
+function queryStringToArray(queryString: string): NameValue[] | undefined {
+  const searchParams = new URLSearchParams(queryString);
+  return searchParamsToArray(searchParams);
+}
+
+function searchParamsToArray(searchParams: URLSearchParams): NameValue[] | undefined {
+  if (searchParams.size === 0)
+    return undefined;
+
+  const result: NameValue[] = [];
+  for (const [name, value] of searchParams.entries())
+    result.push({ name, value });
+  return result;
+}
+
+function mapParamsToArray(params: FetchOptions['params']): NameValue[] | undefined {
+  if (params instanceof URLSearchParams)
+    return searchParamsToArray(params);
+  if (typeof params === 'string')
+    return queryStringToArray(params);
+
+  return objectToArray(params);
+}
+
 function isFilePayload(value: any): boolean {
   return typeof value === 'object' && value['name'] && value['mimeType'] && value['buffer'];
 }
diff --git a/packages/playwright-core/src/server/fetch.ts b/packages/playwright-core/src/server/fetch.ts
index aef805798d..6367e8875e 100644
--- a/packages/playwright-core/src/server/fetch.ts
+++ b/packages/playwright-core/src/server/fetch.ts
@@ -157,7 +157,7 @@ export abstract class APIRequestContext extends SdkObject {
     const requestUrl = new URL(params.url, defaults.baseURL);
     if (params.params) {
       for (const { name, value } of params.params)
-        requestUrl.searchParams.set(name, value);
+        requestUrl.searchParams.append(name, value);
     }
 
     const credentials = this._getHttpCredentials(requestUrl);
diff --git a/packages/playwright-core/types/types.d.ts b/packages/playwright-core/types/types.d.ts
index 91bf8a7d7c..b8bb07747d 100644
--- a/packages/playwright-core/types/types.d.ts
+++ b/packages/playwright-core/types/types.d.ts
@@ -16518,7 +16518,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -16654,7 +16654,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -16754,7 +16754,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -16840,7 +16840,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -16926,7 +16926,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -17054,7 +17054,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
@@ -17140,7 +17140,7 @@ export interface APIRequestContext {
     /**
      * Query parameters to be sent with the URL.
      */
-    params?: { [key: string]: string|number|boolean; };
+    params?: { [key: string]: string|number|boolean; }|URLSearchParams|string;
 
     /**
      * Request timeout in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
diff --git a/tests/library/browsercontext-fetch.spec.ts b/tests/library/browsercontext-fetch.spec.ts
index 733596b481..eb8e8da075 100644
--- a/tests/library/browsercontext-fetch.spec.ts
+++ b/tests/library/browsercontext-fetch.spec.ts
@@ -122,22 +122,40 @@ it('should add session cookies to request', async ({ context, server }) => {
 });
 
 for (const method of ['fetch', 'delete', 'get', 'head', 'patch', 'post', 'put'] as const) {
-  it(`${method} should support queryParams`, async ({ context, server }) => {
-    const url = new URL(server.EMPTY_PAGE);
-    url.searchParams.set('p1', 'v1');
-    url.searchParams.set('парам2', 'знач2');
-    const [request] = await Promise.all([
-      server.waitForRequest(url.pathname + url.search),
-      context.request[method](server.EMPTY_PAGE + '?p1=foo', {
-        params: {
-          'p1': 'v1',
-          'парам2': 'знач2',
-        }
-      }),
-    ]);
-    const params = new URLSearchParams(request.url!.substr(request.url!.indexOf('?')));
-    expect(params.get('p1')).toEqual('v1');
-    expect(params.get('парам2')).toEqual('знач2');
+  it(`${method} should support params passed as object`, async ({ context, server }) => {
+    const params = {
+      'first-param': 'value2',
+      'second-param': 'value',
+    };
+
+    const response = await context.request[method](server.EMPTY_PAGE + '?first-param=value1', { params });
+
+    const { searchParams } = new URL(response.url());
+    expect(searchParams.getAll('first-param')).toEqual(['value1', 'value2']);
+    expect(searchParams.get('second-param')).toBe('value');
+  });
+
+  it(`${method} should support params passed as URLSearchParams`, async ({ context, server }) => {
+    const params = new URLSearchParams();
+    params.append('first-param', 'value1');
+    params.append('first-param', 'value2');
+    params.append('second-param', 'value');
+
+    const response = await context.request[method](server.EMPTY_PAGE, { params });
+
+    const { searchParams } = new URL(response.url());
+    expect(searchParams.getAll('first-param')).toEqual(['value1', 'value2']);
+    expect(searchParams.get('second-param')).toBe('value');
+  });
+
+  it(`${method} should support params passed as string`, async ({ context, server }) => {
+    const params = 'first-param=value1&first-param=value2&second-param=value';
+
+    const response = await context.request[method](server.EMPTY_PAGE, { params });
+
+    const { searchParams } = new URL(response.url());
+    expect(searchParams.getAll('first-param')).toEqual(['value1', 'value2']);
+    expect(searchParams.get('second-param')).toBe('value');
   });
 
   it(`${method} should support failOnStatusCode`, async ({ context, server }) => {