Listen for Puppeteer’s request event, filter for POST requests, and call await request.fetchPostData(). You do not need request interception just to inspect a request body. Because the method returns string | undefined, handle the case where the body is unavailable.
Read a POST body from the request event
Register a listener on the page before the action that triggers the request. The listener receives an HTTPRequest; use request.method() to select POST requests and fetchPostData() to retrieve the body.
As an Amazon Associate I earn from qualifying purchases.
page.on('request', async request => {
if (request.method() !== 'POST' || !request.hasPostData()) {
return;
}
const postData = await request.fetchPostData();
console.log(postData);
});hasPostData() is an optional guard: it reports whether the request has POST data. The result of fetchPostData() can still be undefined, so code that needs to distinguish a readable body from an unavailable one should check it explicitly:
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →page.on('request', async request => {
if (request.method() !== 'POST') return;
const body = await request.fetchPostData();
if (body === undefined) {
console.log('POST body unavailable');
return;
}
console.log(body);
});Attach this listener before submitting a form, clicking a button, or otherwise causing the request. Page request events can include traffic other than the action you care about, so narrow the filter further when needed:
#1 Best Overall
page.on('request', async request => {
if (request.method() !== 'POST' || !request.url().includes('/your-endpoint')) {
return;
}
const body = await request.fetchPostData();
console.log(body);
});Replace /your-endpoint with a distinguishing part of the target URL. Puppeteer’s request events are for page-initiated network requests, not exclusively form submissions.
Why use fetchPostData() instead of postData()?
request.postData() is deprecated. Puppeteer notes that it may be undefined when the data is too long or not readily available in decoded form. Use and await request.fetchPostData() in current code; it fetches the POST data from the browser and resolves to string | undefined. See the Puppeteer HTTPRequest API and the documentation for fetchPostData().
Rank #2
The API documentation does not promise a particular serialization format for every content type. Treat the result as a string and interpret it using the request’s headers and the conventions of the application sending it; do not assume every body is JSON or form-encoded.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Do not enable interception just to read data
The ordinary request event is enough for observation. Request interception is a separate feature for modifying, aborting, or fulfilling requests. Once interception is enabled, each request stalls until it is resolved, unless the browser cache completes it. See Puppeteer’s network and request interception guide.
If interception is already needed for another task, resolve every request on every code path. Other listeners may resolve a request while your handler is awaiting asynchronous work, so check isInterceptResolutionHandled() immediately before calling continue(), abort(), or respond(). Keep the check and resolution call together without an intervening await:
await page.setRequestInterception(true);
page.on('request', async request => {
const body = await request.fetchPostData();
console.log(body);
// Another handler may have resolved it while this handler awaited.
if (request.isInterceptResolutionHandled()) return;
request.continue();
});For interception-specific behavior and coordination details, use the Puppeteer request interception guide. If you do not need to change network traffic, omit interception entirely.
Rank #4
Troubleshoot missing bodies and stalled requests
postData()is undefined: It is deprecated and can be unavailable for long or not-readily-decoded data. Switch toawait request.fetchPostData()and handle an undefined result.fetchPostData()returns undefined: The API allows this result. CheckhasPostData(), inspect the request headers and content type, and confirm that you are handling the request you intended.- The listener catches unrelated requests: Filter by method and, where appropriate, URL or other request properties. A page can initiate multiple requests around one user action.
- Navigation hangs after enabling interception: A request path may not be resolving. Ensure every intercepted request is continued, fulfilled, or aborted, and avoid slow asynchronous work before resolution when possible.
- “Request is already handled!” appears: Another listener or package may have resolved the request. Check
isInterceptResolutionHandled()immediately before resolving, with no asynchronous gap between the check and the call.
The current Puppeteer API and guide pages reviewed identify version 25.12.0; the dedicated fetchPostData() page identifies 25.8.0. Check the documentation matching your installed Puppeteer version if behavior or availability differs.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Or skip the browser setup
ScreenshotNeo is a website screenshot API, not a way to retrieve a page’s POST body. If what you need is a clean screenshot of a URL rather than request data, one GET request returns an image or PDF:
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpSee the ScreenshotNeo documentation for API details. It removes cookie and consent banners, newsletter popups, and chat widgets before capture; bot checks, blank pages, and failed loads are not billed. Its MCP server lets AI agents take screenshots. The free plan includes 1,000 screenshots a month with no card; paid plans start at $5 for 3,000.
Sign up for 1,000 free screenshots a month, with no card.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
