snapdok

Guides · Python · requests

Take a full-page screenshot in Python with requests

"full_page": true captures the whole document, not just the viewport — the render scrolls the page, waits for lazy-loaded images along the way, and returns one tall image. width sets the viewport width the page lays itself out at; height is measured, not guessed.

Below is a complete, runnable Python program using requests (pip install requests). It reads your API key from the SNAPDOK_KEY environment variable — free keys take about thirty seconds and need no card.

import os
import requests

resp = requests.post(
    "https://snapdok.io/v1/render",
    headers={"Authorization": "Bearer " + os.environ["SNAPDOK_KEY"]},
    json={
        "url": "https://your-app.com/report/42",
        "format": "png",
        "full_page": True,
        "width": 1280,
    },
    timeout=90,
)
resp.raise_for_status()

with open("full.png", "wb") as f:
    f.write(resp.content)
print(resp.headers.get("X-Page-Height"), "# measured document height in CSS px")

Very tall pages hit a documented cap rather than an out-of-memory surprise: images are cut off at 20,000 CSS px, and the response says so explicitly — X-Full-Page-Truncated: 1 plus X-Page-Height with the real document height. If you need everything past the cap, ask for "tile": true and the render returns a ZIP of overlapping numbered tiles instead (covered in its own guide, linked below).

Sticky headers are the classic full-page artifact — a bar designed to follow the viewport can repeat down a scrolled capture. If a page renders oddly, try "wait_until": "networkidle" first so animations and late images settle before the scroll pass.

Same endpoint, one more trick: if the page you are rendering has a form on it, adding "pdf_forms": true to a PDF render brings it back with real, fillable AcroForm fields — a PDF people can type into, not a picture of one. How that works.

Notes for requests

Three requests-specific details the sample already handles. resp.content is the binary body — resp.text would decode PDF bytes as text and corrupt them. raise_for_status() turns a JSON error response into an exception instead of letting it reach the open(..., "wb") call. And requests has no default timeout — without the explicit timeout= a hung connection blocks forever, which matters for a call that drives a real browser and legitimately takes seconds.

Response headers worth reading

HeaderMeaning
X-Page-HeightFull document height in CSS px.
X-Full-Page-Truncated1 when the image stops at the 20,000 px cap.
X-Full-Page-Max-HeightThe cap itself.

Full parameter reference: the docs. Hard numbers on caps and timeouts: limits.

Related guides

Same task, other stacks

More with Python + requests