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Use the Chrome DevTools Protocol (CDP) command Page.captureScreenshot on the page target you want to capture. Choose a viewport screenshot, a defined crop, or—where the Chrome version supports it—a capture beyond the viewport. CDP returns image data as base64 in JSON, so decode the response before saving it as a PNG, JPEG, or WebP file.
Send the screenshot command to the right page
Page.captureScreenshot is a command in CDP’s Page domain. Send it through your chosen CDP connection to the target representing the page you want to capture. The protocol message is conceptually:
{"id":1,"method":"Page.captureScreenshot","params":{"format":"png"}}The exact envelope and transport depend on the CDP client or tool you use. In a JSON-based exchange, the response’s result.data contains base64-encoded image data. Decode that value into bytes before writing the file; saving the base64 text itself does not produce a valid image. See the Chromium DevTools Protocol Page.captureScreenshot definition for the protocol fields.
Choose viewport, crop, or full-page capture
Capture the visible viewport
For a normal screenshot of the currently visible page, omit clip and leave captureBeyondViewport disabled. Do not assume this captures content below the viewport.
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Capture a defined region
Set clip to the protocol’s viewport rectangle, including the required position, dimensions, and scale. Check the protocol definition for the target Chrome version when constructing the clip; incorrect geometry or scale can shift, resize, or truncate the result.
Capture beyond the viewport
For content extending outside the visible viewport, use captureBeyondViewport where the target Chrome build supports it. Determine the page’s actual content dimensions rather than assuming they equal the configured viewport dimensions. Chromium’s protocol schema marks this field experimental in version 140, so check versioned protocol metadata and test against the Chrome build you deploy.
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The fromSurface and optimizeForSpeed fields are also marked experimental in Chromium’s version 140 schema. Experimental fields can vary by protocol version; do not assume availability or identical behavior across Chrome builds.
Set output format and quality
| Parameter | What it does | Practical choice |
|---|---|---|
format |
Selects png, jpeg, or webp. PNG is the default. |
Use PNG when lossless output matters; choose JPEG or WebP when their output better suits your storage or delivery needs. |
quality |
An integer from 0 to 100; applies to JPEG. | Set a value when you choose JPEG and need to balance image quality against file size. The protocol definition does not prescribe one ideal value. |
clip |
Restricts the screenshot to a specified region. | Supply valid geometry and scale from the protocol definition. |
captureBeyondViewport |
Allows capture beyond the visible viewport where supported. | Check the Chrome build’s protocol support and the actual content dimensions. |
PNG is lossless; JPEG is lossy and accepts the documented 0–100 quality range. WebP is also supported by the protocol schema. Consult the protocol definition for the current field requirements and the versioned schema for experimental status.
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Send a command interactively with Protocol Monitor
Chrome DevTools Protocol Monitor lets you send CDP commands and inspect their requests and responses without writing a separate automation client. Enable the Protocol Monitor experiment if needed, open it from the Command menu or More tools, and select the page target before sending a command.
- Open DevTools and enable the Protocol Monitor experiment if it is not already enabled.
- Open Protocol Monitor using the Command menu or More tools.
- Select the intended page target so the command reaches the page you want to capture.
- Enter the command and arguments, then send it. For example, to request JPEG output, use
{"cmd":"Page.captureScreenshot","args":{"format":"jpeg"}}. - Inspect the response, decode its base64 image data, and save the resulting bytes with the matching file extension.
The structured command editor can also build a form from protocol definitions. See Chrome’s Protocol Monitor guide for its setup and controls.
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Use a built-in alternative when raw CDP is unnecessary
| Option | Best fit | Scope and difference |
|---|---|---|
Page.captureScreenshot |
Direct protocol integration | Viewport, clip, and beyond-viewport options; your client handles transport and image decoding. |
| Protocol Monitor | Manual exploration or debugging | Sends one-off commands to a selected target and displays requests and responses. |
| DevTools Device Mode | Manual visual checks | Offers viewport and full-size page screenshots through the DevTools interface. |
Headless Chrome --screenshot |
Simple command-line capture | Saves screenshot.png in the current working directory; the documented CLI workflow does not require constructing a CDP message. |
| Puppeteer | Scripted browser automation | A higher-level JavaScript library that works with Chrome and Firefox over CDP and WebDriver BiDi; its overview describes full-page and element screenshots. |
Device Mode for manual captures
In DevTools Device Mode, choose Capture screenshot for the visible viewport or Capture a full size screenshot for the page content beyond it. DevTools also documents node, oversized-node, mobile/device-frame, and area captures. See Chrome’s Device Mode screenshot instructions.
Headless Chrome for a command-line capture
Chrome’s --screenshot flag captures a target page and saves screenshot.png in the current working directory. The official example combines the flag with --window-size=412,892. Use --timeout to set a maximum wait before capture, including when page content is still loading. Consult Chrome’s Headless screenshot documentation for the documented command-line workflow.
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Puppeteer for a scripted workflow
Choose Puppeteer when you want a browser automation library rather than direct CDP message handling. Its overview covers Chrome and Firefox support over CDP and WebDriver BiDi, as well as full-page and specific-element screenshots. See the Puppeteer documentation.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Troubleshoot common capture problems
- The screenshot is only viewport-sized: A default capture is not automatically a full-page capture. Check whether the target Chrome version supports
captureBeyondViewport, enable it when appropriate, and account for the page’s actual content dimensions. - The cropped image is misplaced or the wrong size: Verify the clip rectangle’s position, dimensions, and scale against the protocol definition for your Chrome version.
- The saved file is invalid: Treat the JSON response’s
result.dataas base64 image data. Decode it to binary bytes and use a file extension matching the requested format. - The requested format or option is rejected: Check the command’s parameter spelling and the target build’s protocol schema. Experimental parameters, including
fromSurface,captureBeyondViewport, andoptimizeForSpeedin Chromium’s version 140 schema, may not be available in every build. - Chrome’s extension debugger reports “Screenshot capture is restricted by policy”: For the Chrome extension
browser.debuggerAPI, enterpriseDisableScreenshotspolicy or Data Loss Prevention rules can block capture and cause debugger attachment to fail. This restriction is documented for that extension API; it should not be assumed to affect every remote-debugging transport. See Chrome’s debugger API documentation.
Or skip the browser setup
ScreenshotNeo is a website screenshot API and MCP server. A single GET request returns an image or PDF; its API handles the browser capture rather than requiring you to set up and manage a CDP connection. Cookie banners, newsletter popups, and chat widgets are removed before the shot. Bot checks, blank pages, timeouts, failed loads, and cache hits are not billed, and the response identifies page verdict and billing status in headers. Its MCP server gives AI agents tools to take screenshots, get page information, and capture PDFs.
Here is a cURL example; replace the target URL and API key with your own. See the ScreenshotNeo documentation for request options and setup.
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Frequently Asked Questions
Which CDP command captures a webpage screenshot?
Use Page.captureScreenshot in the Page domain on the page target you intend to capture.
What does CDP return from a screenshot request?
In a JSON transport, the response contains base64-encoded image data. Decode it to bytes before saving the image.
Quick Recap
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