Free Screenshot API for Developers

Need to capture website screenshots programmatically? Whether you're building link previews, generating thumbnails for a CMS, testing responsive layouts, or creating visual reports — you need a screenshot API that's fast, flexible, and doesn't cost a fortune.

Most screenshot APIs charge $29-99/month even for basic usage. We built a free screenshot API that gives you 50 credits with no signup, supports 5 viewport presets, full-page capture, dark mode, and CSS selector targeting.

Quick Start: 3 Steps

1. Get a free API key

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/keys/create

{
  "key": "ss_abc123...",
  "credits": 50,
  "note": "50 free credits. Top up with USDC on Base.",
  "check_balance": "GET /api/keys/balance with Authorization: Bearer YOUR_KEY"
}

2. Take a screenshot

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com"}'

3. Get the image

The response contains a download URL or base64-encoded image data. Use the /api/screenshot/json endpoint for inline base64:

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com", "viewport": "mobile"}'

{
  "id": "scr_86071bdde86f087d",
  "image": "iVBORw0KGgoAAAANSUhEUg...",
  "format": "png",
  "url": "https://example.com/",
  "title": "Example Domain",
  "viewport": {"width": 375, "height": 812},
  "fullPage": false,
  "size": 17299,
  "takenAt": "2026-03-03T15:10:09.640Z"
}

Features

API Reference

Code Examples

# Desktop screenshot
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://github.com"}'

# Mobile viewport, full page, dark mode
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://github.com", "viewport": "mobile", "fullPage": true, "darkMode": true}'

# Capture specific element
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://github.com", "selector": ".application-main"}'

# Wait for dynamic content
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com", "delay": 3000}'

import requests
import base64

API = "https://agent-gateway-kappa.vercel.app/v1/agent-screenshot"

# Step 1: Get free API key
key_resp = requests.post(f"{API}/api/keys/create")
api_key = key_resp.json()["key"]
print(f"API Key: {api_key}")

headers = {"Authorization": f"Bearer {api_key}"}

# Step 2: Take screenshot (returns base64)
resp = requests.post(
    f"{API}/api/screenshot/json",
    headers=headers,
    json={
        "url": "https://news.ycombinator.com",
        "viewport": "desktop",
        "fullPage": True
    }
)
data = resp.json()

# Step 3: Save to file
img_bytes = base64.b64decode(data["image"])
with open("screenshot.png", "wb") as f:
    f.write(img_bytes)

print(f"Saved: {data['title']} ({data['size']} bytes)")
# Output: Saved: Hacker News (45123 bytes)

# Batch screenshots across viewports
for viewport in ["desktop", "tablet", "mobile"]:
    resp = requests.post(
        f"{API}/api/screenshot/json",
        headers=headers,
        json={"url": "https://example.com", "viewport": viewport}
    )
    img = base64.b64decode(resp.json()["image"])
    with open(f"screenshot-{viewport}.png", "wb") as f:
        f.write(img)
    print(f"{viewport}: {len(img)} bytes")

const fs = require('fs');

const API = 'https://agent-gateway-kappa.vercel.app/v1/agent-screenshot';

async function captureScreenshot() {
  // Step 1: Get free API key
  const keyResp = await fetch(`${API}/api/keys/create`, { method: 'POST' });
  const { key } = await keyResp.json();
  console.log(`API Key: ${key}`);

  // Step 2: Take screenshot
  const resp = await fetch(`${API}/api/screenshot/json`, {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${key}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      url: 'https://github.com',
      viewport: 'desktop',
      darkMode: true
    })
  });
  const data = await resp.json();

  // Step 3: Save to file
  const buffer = Buffer.from(data.image, 'base64');
  fs.writeFileSync('screenshot.png', buffer);
  console.log(`Saved: ${data.title} (${data.size} bytes)`);
}

captureScreenshot();

Use Cases

Link Previews & Social Cards

Automatically generate link preview thumbnails for your app. When a user pastes a URL, capture a screenshot and display it as a rich preview — like Slack, Discord, or Twitter do.

# Generate a link preview thumbnail
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com", "viewport": "desktop", "format": "jpeg"}'

Responsive Design Testing

Capture the same page across all 5 viewports to verify your responsive design. Automate visual regression tests in CI/CD pipelines.

# Compare desktop vs mobile rendering
for vp in desktop tablet mobile 1080p 4k; do
  curl -s -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
    -H "Authorization: Bearer YOUR_KEY" \
    -H "Content-Type: application/json" \
    -d "{\"url\": \"https://yoursite.com\", \"viewport\": \"$vp\"}" \
    | python3 -c "import sys,json,base64; d=json.load(sys.stdin); open(f'$vp.png','wb').write(base64.b64decode(d['image']))"
  echo "Captured $vp"
done

SEO & Competitor Monitoring

Take daily screenshots of competitor websites or your own SERP rankings. Track design changes, pricing updates, and content modifications over time.

Documentation & Reporting

Generate screenshots for documentation, status reports, or client presentations. Use fullPage: true to capture entire pages, or selector to grab specific UI components.

Dark Mode Testing

Test how your website looks in both light and dark modes without manually switching. The darkMode parameter emulates the prefers-color-scheme: dark media query.

# Compare light vs dark mode
curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://github.com", "darkMode": false}'

curl -X POST https://agent-gateway-kappa.vercel.app/v1/agent-screenshot/api/screenshot/json \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://github.com", "darkMode": true}'

Comparison: Screenshot APIs in 2026

Viewport Presets

Build a Screenshot Automation Script

Here's a complete Python script that monitors a list of URLs and captures daily screenshots for visual change tracking:

import requests, base64, os
from datetime import datetime

API = "https://agent-gateway-kappa.vercel.app/v1/agent-screenshot"

# Get API key (save this, reuse across runs)
def get_key():
    key = os.environ.get("SCREENSHOT_KEY")
    if not key:
        resp = requests.post(f"{API}/api/keys/create")
        key = resp.json()["key"]
        print(f"New key: {key} (save as SCREENSHOT_KEY env var)")
    return key

# Capture screenshots for multiple URLs
def capture_batch(urls, viewport="desktop"):
    key = get_key()
    headers = {"Authorization": f"Bearer {key}"}
    today = datetime.now().strftime("%Y-%m-%d")
    os.makedirs(today, exist_ok=True)

    for url in urls:
        resp = requests.post(
            f"{API}/api/screenshot/json",
            headers=headers,
            json={"url": url, "viewport": viewport, "fullPage": True}
        )
        data = resp.json()
        slug = url.replace("https://", "").replace("/", "_")
        path = f"{today}/{slug}.png"
        with open(path, "wb") as f:
            f.write(base64.b64decode(data["image"]))
        print(f"[OK] {data['title']} -> {path}")

# Usage: monitor these sites daily
sites = [
    "https://news.ycombinator.com",
    "https://github.com/trending",
    "https://producthunt.com",
]
capture_batch(sites)

Frequently Asked Questions

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