How BLS CAPTCHA Works: Grid Logic and Image Selection

BLS CAPTCHA is a custom image-based challenge used on BLS International visa appointment portals. Unlike reCAPTCHA's standardized grid, BLS uses its own image selection system with unique grid layouts, instruction patterns, and validation logic. Understanding how the grid works helps you build reliable solving workflows.

Grid structure

BLS CAPTCHAs present a set of images in a grid layout. The grid is not always uniform — it varies by implementation.

Grid type	Layout	Image count
Small grid	1×3 or 1×4	3–4 images in a row
Medium grid	2×3 or 2×4	6–8 images
Large grid	3×3	9 images (similar to reCAPTCHA)

Each image is a distinct object — not tiles from a single larger image. This is a key difference from reCAPTCHA, where a single photo is split into a grid.

How instructions work

The CAPTCHA presents a text instruction above the grid. The user must select all images matching the description.

Common instruction patterns:

"Select all images with a car"
"Click the image showing a bicycle"
"Select the traffic light"
"Choose all images containing a bridge"

The instruction always identifies a single object category. Unlike reCAPTCHA, BLS does not use multi-step challenges or dynamic grid refills.

Image selection logic

Instruction parsing — The solving system reads the instruction to identify the target object
Image analysis — Each grid image is analyzed individually
Matching — Images containing the target object are identified
Response — The indices of matching images are returned

The response is an array of 1-based indices:

Grid layout (2×3):
1  2  3
4  5  6

Instruction: "Select all images with a car"
Cars found in images 2 and 5
Response: [2, 5]

BLS vs reCAPTCHA grid differences

Feature	BLS CAPTCHA	reCAPTCHA v2 Grid
Image source	Distinct separate images	Single image split into tiles
Grid size	Variable (3–9 images)	Fixed (3×3 or 4×4)
Multi-step	No — single selection	Yes — grid may refill
Instruction language	Matches site language (varies by country)	English
Provider	BLS International (proprietary)	Google
Validation	BLS backend	Google API
Solving method	Image analysis per cell	Image analysis per tile

How CaptchaAI processes BLS

When you submit a BLS CAPTCHA to CaptchaAI:

You send the full grid image and the instruction text
CaptchaAI identifies the grid layout (row × column count)
Each cell is analyzed against the instruction
Matching cell indices are returned

The critical parameters:

Parameter	Purpose
`instructions`	The text instruction from the CAPTCHA ("Select all images with a car")
`img_type`	Set to the appropriate type for BLS
`grid_size`	Grid dimensions (e.g., "2x3", "3x3")

Instruction language considerations

BLS portals serve different countries, and instructions may appear in the local language:

Country portal	Instruction language
Italy BLS	Italian or English
Spain BLS	Spanish or English
Portugal BLS	Portuguese or English
India BLS	English

When submitting to CaptchaAI, send the instruction exactly as it appears on the page. CaptchaAI handles multilingual instructions.

Why BLS CAPTCHAs fail

Reason	Impact	Fix
Wrong grid size	Indices map to wrong cells	Count images and set correct grid_size
Instruction not included	Solver does not know what to select	Always send the instruction text
Cropped image	Missing cells, wrong analysis	Capture the full grid image
Dynamic image loading	Images load asynchronously, some missing	Wait for all images to load before capture

Grid numbering

BLS grid cells are numbered left-to-right, top-to-bottom — the same as reCAPTCHA:

2×3 grid:     3×3 grid:     1×4 grid:
1  2  3       1  2  3       1  2  3  4
4  5  6       4  5  6
              7  8  9

When clicking the selected cells in your automation, use this numbering to map indices to DOM elements.

FAQ

Is BLS CAPTCHA the same as reCAPTCHA?

No. BLS uses a proprietary image selection system. It looks similar to reCAPTCHA's image grid but uses distinct images instead of tiles from a single photo, and it has no multi-step challenges.

Does BLS CAPTCHA change frequently?

BLS updates their CAPTCHA implementation periodically. The core grid-and-instruction format has remained stable, but image sets and instruction wording may change.

Can I solve BLS CAPTCHA with the reCAPTCHA method?

No. BLS is not reCAPTCHA. Use the appropriate CaptchaAI method for BLS image recognition, not userrecaptcha.

How accurate is BLS CAPTCHA solving?

High accuracy when the full grid image and correct instruction are provided. Most failures come from wrong grid_size or missing instruction text.

Solve BLS CAPTCHAs with CaptchaAI

Automate visa appointment CAPTCHA handling at captchaai.com.