Automate Form Submissions with Real Browsers

Pass CAPTCHA, fingerprint checks, and JS validation. Fill forms programmatically with authentic sessions.

The Problem

Web forms increasingly use bot detection: CAPTCHA challenges, JavaScript fingerprinting, and behavioral analysis. Headless browsers trigger these defenses immediately.

Multi-step forms with dynamic validation, file uploads, and conditional fields break simple HTTP-based automation. You need a real browser that can execute JavaScript.

Traditional automation tools leave detectable traces: missing plugins, wrong screen resolution, unnatural mouse movement patterns.

How Ceki Solves This

  • ✓ Real browsers pass fingerprint checks — no CAPTCHA triggers
  • ✓ Full JavaScript execution for dynamic forms and conditional logic
  • ✓ Fill, click, select, upload — all standard form interactions supported
  • ✓ Chain multiple steps: navigate, fill, submit, extract confirmation

Quick Example

import asyncio, os
from ceki_browser import connect

async def main():
    client = await connect(os.environ["CEKI_API_KEY"])
    options = await client.search({"geo": "US"})
    browser = await client.rent(options[0].schedule_id)

    await browser.navigate("https://example.com/apply")
    await browser.click(400, 200)
    await browser.type("john@example.com")
    snap = await browser.snapshot()
    print(snap.title)

    await browser.close()
    await client.close()

asyncio.run(main())
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FAQ

Other Use Cases

🌐Web Scraping🌍Testing📱Social Media

Automating Form Submissions Without Getting Blocked: A Technical Guide

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Form filling automation faces a unique challenge: forms are specifically designed to stop bots. CAPTCHAs, honeypot fields, JavaScript validation, timing checks, and fingerprint verification all aim to ensure that a human — not a script — is filling out the form.

Why form automation is harder than scraping

Scraping is passive — you read data from a page. Form filling is active — you submit data that triggers server-side processing. Websites invest more in protecting forms because form submissions have real consequences: account creation, purchases, applications, comments.

Common protections on forms in 2026: reCAPTCHA v3 (invisible scoring based on behavior), hCaptcha (challenge-based), Cloudflare Turnstile (passive verification), hidden honeypot fields, JavaScript timing validation (submit too fast = bot), device fingerprint matching, and session token validation.

Real browsers + human-in-the-loop = reliable form automation

Real browser sessions solve most of these problems automatically. reCAPTCHA v3 scores are high because the browser IS a real browser. Cloudflare Turnstile passes because the fingerprint is genuine. Honeypot fields aren't filled because you control the DOM precisely. Timing can be natural with human-like delays. Fingerprints match because it's the same real browser throughout.

For challenge CAPTCHAs that require visual solving (reCAPTCHA v2, hCaptcha), the human-in-the-loop feature lets your agent request the host to solve it. The host sees the CAPTCHA, solves it, and the agent continues — all within the same session, same fingerprint, same IP.

Multi-step form workflows

Many real-world forms span multiple pages: registration flows, application processes, checkout sequences. Each step validates the previous one and expects consistent browser state.

With real browser sessions, your agent handles multi-step forms naturally. The browser maintains state across pages — cookies, session tokens, form data. Navigate to step 1, fill fields, submit, wait for step 2, fill, submit, and so on. The browser behaves exactly like a human working through the form.

Practical code patterns

Key patterns for reliable form filling: use natural typing delays (50-150ms between keystrokes), click form fields before typing (don't just set values via JS), scroll to form elements before interacting, wait for page loads between steps, handle dynamic form validation (wait for error messages to clear), and take screenshots after each step for verification.