Guides · Python · requests

Capture very tall pages as numbered tiles in Python with requests

A single image has a height cap (20,000 CSS px) because somewhere past that, image viewers and memory both give up. "tile": true is the opt-in for pages that run past it: instead of cutting the capture off, the API returns a ZIP of numbered PNG tiles that cover the entire document.

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/changelog",
        "format": "png",
        "full_page": True,
        "tile": True,
    },
    timeout=90,
)
resp.raise_for_status()

with open("page-tiles.zip", "wb") as f:
    f.write(resp.content)
print(resp.headers.get("X-Tiles"), "# how many parts are in the ZIP")

The tiles overlap on purpose: each part starts 80 px above where the previous one ended, so the seam appears in both images and nothing can fall into a gap — line up the repeated rows and you have the whole page. The archive includes a README stating each part's y-range, and the response carries the numbers too: X-Tiles (count), X-Tile-Overlap (the 80 px), and X-Page-Height.

Note the response type changes: with tiling you receive application/zip, not image/png — code that assumes an image must branch on Content-Type. Pages short enough for one image return a plain PNG even with tile set, so the branch is required, not theoretical. That asymmetry is deliberate: a screenshot is one image to almost everyone, so the archive only happens when you asked for it and the page needs it.

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

Header	Meaning
`Content-Type`	application/zip when tiled, image/png when not needed.
`X-Tiles`	Number of parts in the archive.
`X-Tile-Overlap`	Vertical overlap between parts, in CSS px.

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

Capture very tall pages as numbered tiles in Python with requests

Notes for requests

Response headers worth reading

Related guides

Same task, other stacks

More with Python + requests