Explainers

How BLS CAPTCHA Works

BLS CAPTCHA is a custom image verification challenge used on BLS International visa appointment booking systems. Unlike standardized CAPTCHAs (reCAPTCHA, Turnstile), BLS uses its own implementation with multi-image selection based on text instructions.

This CAPTCHA appears during appointment booking flows for visa services in countries including Italy, Spain, Portugal, and others that use BLS as their visa processing partner.


How the challenge works

  1. Page loads — The BLS appointment form includes a captcha section
  2. Images displayed — 3–9 distinct images appear in a grid
  3. Instruction shown — Text above the grid says something like "Select all images with a car" or "Click the image showing a bicycle"
  4. User selects — The user clicks the correct images
  5. Submission — The selected image indices are sent to the BLS backend
  6. Verification — The server validates the selection and allows form submission

Challenge format

┌─────────────────────────────────────────────┐
│  "Select all images with a motorcycle"       │
├────────────┬────────────┬────────────────────┤
│  [Image 1] │  [Image 2] │  [Image 3]         │
│   🚗 Car   │  🏍️ Moto  │  🚌 Bus            │
├────────────┼────────────┼────────────────────┤
│  [Image 4] │  [Image 5] │  [Image 6]         │
│  🏍️ Moto  │  🚂 Train  │  ✈️ Plane          │
└────────────┴────────────┴────────────────────┘
Answer: Images 2 and 4

BLS vs reCAPTCHA image challenges

Feature BLS CAPTCHA reCAPTCHA Grid
Source Custom BLS implementation Google
Image format Separate distinct images Single image split into grid
Dynamic tiles No Yes (new tiles fade in)
Categories Varied (vehicles, objects, animals) Fixed (traffic lights, crosswalks, buses)
Behavioral analysis Minimal Extensive (mouse, timing, cookies)
Difficulty Moderate Moderate to hard
Standardized API No Yes (sitekey-based)

Where BLS CAPTCHA appears

BLS CAPTCHA is found on BLS International appointment systems:

  • Visa appointment booking — The primary use case
  • Appointment rescheduling — Some centers require captcha for changes
  • Status checking — Some portals require captcha for tracking

Common domains:

  • blsitalypakistan.com
  • blsspainvisa.com
  • blsportugal.com
  • Various country-specific BLS portals

Why BLS uses custom CAPTCHA

BLS appointment systems face heavy bot traffic because:

  1. Limited slots — Visa appointments are scarce and in high demand
  2. High value — Each appointment slot has significant value
  3. Resale market — Bots book and resell appointment slots
  4. Prevention — Custom CAPTCHA is harder to solve with generic tools

By using a non-standard CAPTCHA, BLS makes it harder for generic CAPTCHA-solving tools that only support reCAPTCHA or Turnstile.


Solving BLS CAPTCHA

CaptchaAI supports BLS CAPTCHA through the method=bls parameter:

import requests
import time

response = requests.post("https://ocr.captchaai.com/in.php", data={
    "key": "YOUR_API_KEY",
    "method": "bls",
    "instructions": "Select all images with a motorcycle",
    "image_base64_1": "<base64_image_1>",
    "image_base64_2": "<base64_image_2>",
    "image_base64_3": "<base64_image_3>",
    "image_base64_4": "<base64_image_4>",
    "image_base64_5": "<base64_image_5>",
    "image_base64_6": "<base64_image_6>",
    "json": 1
})

task_id = response.json()["request"]

for _ in range(30):
    time.sleep(5)
    result = requests.get("https://ocr.captchaai.com/res.php", params={
        "key": "YOUR_API_KEY", "action": "get", "id": task_id, "json": 1
    }).json()
    if result.get("status") == 1:
        # Returns indices like "2,4"
        print(f"Select images: {result['request']}")
        break

FAQ

Is BLS CAPTCHA the same as reCAPTCHA?

No. BLS uses a custom captcha implementation, not Google's reCAPTCHA. It requires a different solving approach (method=bls vs method=userrecaptcha).

How many images does BLS CAPTCHA show?

Typically 3–9 images per challenge. The number varies by the specific BLS portal and session.

Does BLS CAPTCHA change frequently?

BLS periodically updates their CAPTCHA implementation. The core format (image selection with text instructions) has remained consistent.

Can I solve BLS CAPTCHA with OCR?

OCR alone is insufficient because BLS CAPTCHA requires image recognition (identifying objects), not text recognition. CaptchaAI uses image classification models to identify the correct images.


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