# Bypass Kasada

 94% success on Kasada-protected targets. One API parameter.

##  PoW solved once. `kas_challenge` replayed. Session cached. 

- **Real browser fingerprints.** [TLS](https://scrapfly.io/web-scraping-tools/ja3-fingerprint), [HTTP/2](https://scrapfly.io/web-scraping-tools/http2-fingerprint), [Canvas](https://scrapfly.io/web-scraping-tools/canvas-fingerprint), and [WebGL](https://scrapfly.io/web-scraping-tools/webgl-fingerprint) all match real Chrome on every request.
- **Adaptive challenge solving.** [JavaScript execution](https://scrapfly.io/docs/scrape-api/javascript-rendering), CAPTCHAs, proof-of-work, handled without solver keys.
- **Session intelligence.** Unblocked browser sessions reused across requests so Kasada sees a single coherent visitor.
 
**One API parameter.** Add `asp=True`. See the [ASP docs](https://scrapfly.io/docs/scrape-api/anti-scraping-protection).

 [Get Free API Key](https://scrapfly.io/register) [Read ASP docs](https://scrapfly.io/docs/scrape-api/anti-scraping-protection) 

 1,000 free credits. No credit card required. 

 

   

 FINGERPRINT DATA  LIVE  

















 

 

 + 4,000 more datapoints... 

 

 4,000+

 Fingerprint Datapoints 

200M+

 Proxy IPs 

50+

 Anti-Bots 

 



 

 

 

 

 

---

 COVERAGE## Every Kasada Signal, Matched

Bit-for-bit fingerprint parity with real Chrome. Not monkey-patching, not surface-level, engineered at the protocol and C++ layers.

 

 ##### kas.js Puzzle Solved. kas\_challenge Token Signed.

Kasada forces every first-time visitor to solve a proof-of-work puzzle in the browser. The puzzle is cheap for a real browser and expensive in aggregate for a botnet. On top, the `kas.js` collector reads fingerprint + behavioral signals and emits a signed `kas_challenge` token. Scrapfly solves both inside Scrapium once, then reuses the unblocked session so the cost per page stays predictable.

**94%**success on kasada

**kas.js**collector payload valid

**kas\_challenge**PoW token signed

**1,000+**protected sites coverage

 





 

 

 ##### Proof-of-Work + kas\_challenge

Kasada's PoW runs in a web worker; the answer is cryptographically signed into `kas_challenge` and attached via `x-kasada-*` headers. Without matching TLS + browser fingerprint, the token is rejected even if the PoW math is correct.

PoW worker

kas\_challenge

x-kasada headers

\_\_kasada object

 

 





 ##### Why DIY Bypasses Fail

Solving the PoW math alone gets you nowhere, the collector payload still has to verify.

 | **curl-impersonate** | no kas.js execution |
|---|---|
| **kasada-bypass (OSS)** | abandoned per rotation |
| **Playwright + stealth** | collector leaks |
| **Selenium** | timing signals off |
| **Scrapfly** | 94%, tracked daily |

 





 

 ##### PoW Caching

Scrapfly solves once, caches the unblocked session, reuses across requests. Bot PoW cost amortizes to ~free.

 **once** solve per session 

 





 ##### Device Fingerprint, C++ Patches

Kasada reads Canvas, WebGL, AudioContext, Navigator, and timing signals. Scrapium patches each at Chromium source level, JS-hook detection via `toString()` sees native bindings.

[Canvas](https://scrapfly.io/web-scraping-tools/canvas-fingerprint)

[WebGL](https://scrapfly.io/web-scraping-tools/webgl-fingerprint)

[Audio](https://scrapfly.io/web-scraping-tools/audio-fingerprint)

Navigator

Timing

Plugins

 

 





 ##### Scalper Pressure

Kasada is heavy on sites under active scalper pressure: concert tickets, sneaker drops, gaming.

- Ticketing
- Sneakers
- Gaming
 
 





 

 ##### Kasada Detection Stack, Every Layer Matched

Kasada chains TLS → kas.js collector → PoW worker → kas\_challenge token → `x-kasada-*` header validation. Fail one, block follows.

 **TLS + HTTP/2**Chrome wire format at edge

 

 **kas.js Collector**payload signed under real Chrome

 

 **Proof-of-Work**solved once, unblocked session cached

 

 **kas\_challenge Token**x-kasada-\* headers replayed coherently

 

 

 





 ##### TLS + kas.js Collector

Kasada fingerprints TLS at the edge and cross-checks the `kas.js` collector payload server-side.

- JA4 match, Chrome-identical
- HTTP/2 SETTINGS aligned
- Collector payload signed valid
- Behavioral signals coherent
 
 





 

 

---

 PROOF## One Parameter. Kasada Cleared.

Add `asp=True`. Scrapfly detects Kasada and routes through the correct engine, Curlium for HTTP-layer targets, Scrapium for JS-heavy ones.

 

Set `asp=True` and Scrapfly handles Kasada automatically. Picks [Curlium](https://scrapfly.io/curlium) or [Scrapium](https://scrapfly.io/scrapium) per target.

     Python TypeScript Go Rust HTTP / cURL  

      

 ```
from scrapfly import ScrapeConfig, ScrapflyClient, ScrapeApiResponse
client = ScrapflyClient(key="API KEY")

api_response: ScrapeApiResponse = client.scrape(
    ScrapeConfig(
        url='https://httpbin.dev/html',
        # bypass anti-scraping protection
        asp=True
    )
)
print(api_response.result)
```

 ```
import { 
    ScrapflyClient, ScrapeConfig 
} from 'jsr:@scrapfly/scrapfly-sdk';

const client = new ScrapflyClient({ key: "API KEY" });
let api_result = await client.scrape(
    new ScrapeConfig({
        url: 'https://httpbin.dev/html',
        // bypass anti-scraping protection
        asp: true,
    })
);
console.log(api_result.result);
```

 ```
package main

import (
	"fmt"
	"github.com/scrapfly/go-scrapfly"
)

func main() {
	client, _ := scrapfly.New("API KEY")
	result, _ := client.Scrape(&scrapfly.ScrapeConfig{
		URL: "https://httpbin.dev/html",
		// bypass anti-scraping protection
		ASP: true,
	})
	fmt.Println(result.Result.Content)
}
```

 ```
use scrapfly_sdk::{Client, ScrapeConfig};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::builder().api_key("API KEY").build()?;

    let cfg = ScrapeConfig::builder("https://httpbin.dev/html")
        // bypass anti-scraping protection
        .asp(true)
        .build()?;

    let result = client.scrape(&cfg).await?;
    println!("{}", result.result.content);
    Ok(())
}
```

 ```
http https://api.scrapfly.io/scrape \
key==$SCRAPFLY_KEY \
url==https://httpbin.dev/html \
asp==true
```

 

 

 // RESPONSE    json  

 ```
{
  "result": {
    "status_code": 200,
    "success": true,
    "url": "https://httpbin.dev/html",
    "content": "<html>...</html>",
    "content_format": "raw",
    "content_type": "text/html; charset=utf-8",
    "response_headers": {
      "content-type": "text/html; charset=utf-8",
      "server": "cloudflare"
    },
    "cookies": [],
    "duration": 1842,
    "log_url": "https://scrapfly.io/dashboard/monitoring/log/01J...",
    "asp_cost": 30
  },
  "context": {
    "asp": true,
    "proxy": {
      "country": "us",
      "type": "datacenter"
    }
  }
}
```

 

 

 

 [ Python SDK docs → ](https://scrapfly.io/docs/sdk/python) [ TypeScript SDK docs → ](https://scrapfly.io/docs/sdk/typescript) [ Go SDK docs → ](https://scrapfly.io/docs/sdk/golang) [ Rust SDK docs → ](https://scrapfly.io/docs/sdk/rust) [ HTTP API docs → ](https://scrapfly.io/docs) 

 

 

 [ Get Free API Key ](https://scrapfly.io/register) [ Read the Bypass Guide → ](https://scrapfly.io/blog/posts/how-to-bypass-kasada-anti-scraping-waf) 

 

---

  FAQ## Frequently Asked Questions

 

  ### Can I test on my specific Kasada targets?

 Yes. The free plan includes 1,000 API credits with no credit card required. Enable `asp=True` and test your exact targets before committing. Scrapfly achieves 94% success on Kasada-protected sites; failed requests are not charged.

 

   ### How much does ASP cost?

 ASP starts at 30+ credits per request, scaling with target complexity. You pay for what a specific target needs, not a flat premium. See [pricing](https://scrapfly.io/pricing).

 

   ### What is Kasada's proof-of-work?

 Kasada forces every first-time visitor to solve a computational puzzle in the browser before the real response is served. The puzzle is short for a real browser and expensive in aggregate for a botnet. Scrapfly solves the puzzle inside Scrapium then reuses the unblocked session, so the cost per page stays predictable. DIY guide: [bypassing Kasada](https://scrapfly.io/blog/posts/how-to-bypass-kasada-anti-scraping-waf).

 

   ### Where is Kasada deployed?

 Ticketing, gaming, and e-commerce. Kasada is particularly common on sites under active scalper pressure, concerts, sneaker drops, online gambling. The kas.js collector runs on every page and produces a signed kas\_challenge token that must match the HTTP request.

 

  

 

  ---

 // SEE ALSO### Bypass every other major anti-bot vendor too.

ASP handles every major anti-bot stack with the same flag. Switch targets, keep the parameter.

 [Cloudflare](https://scrapfly.io/bypass/cloudflare) 

 [Akamai](https://scrapfly.io/bypass/akamai) 

 [DataDome](https://scrapfly.io/bypass/datadome) 

 [PerimeterX](https://scrapfly.io/bypass/perimeterx) 

 [Incapsula](https://scrapfly.io/bypass/incapsula) 

 [F5](https://scrapfly.io/bypass/f5) 

 [AWS WAF](https://scrapfly.io/bypass/aws-waf) 

 

 

 [Get Free API Key](https://scrapfly.io/register) [View all anti-bot bypasses](https://scrapfly.io/bypass)