Conversion Pixel

A conversion pixel is the browser-side way to report a conversion. You place a tiny snippet on the page a visitor reaches after they convert — the order confirmation, the "thanks for signing up" page — and when that page loads, the pixel fires a request to the tracking platform saying "a conversion just happened here." It typically renders as an invisible 1×1 transparent image, so it can never visibly break your page.

Pixel, iframe, or postback

There are three ways to report the same conversion:

• Image pixel (GET). An <img> tag on the confirmation page. Easiest to install; always returns a transparent GIF and never visibly fails.
• Iframe pixel (GET). Records identically but returns a small sandboxed document — needed if your affiliates run their own HTML pixels.
• Server-to-server postback (POST). Your server fires directly, the most reliable path and the only safe way to send personal data.

Use the image pixel for a simple single-domain thank-you page; use a postback whenever reliability or privacy matters.

A worked example

Your checkout success page includes:

<img src="https://track.yourbrand.com/conv?ll_cid=CLICK_ID&txn=order-8837&event=2&rev=250"
             width="1" height="1" style="display:none" alt="">
        

You replace CLICK_ID with the visitor's real click ID (read from the landing URL earlier in the funnel) and order-8837 with the real order number — the transaction ID that makes re-fires idempotent. When the page loads, the platform matches the click, credits the affiliate, and records $250 in revenue.

The pitfalls

A conversion pixel depends on the browser: ad blockers, strict privacy settings, and cross-domain funnels can all stop it from firing or from reading the click ID. If the pixel fires without a click ID, the platform falls back to the first-party cookie — and if that is unavailable, the conversion is unattributed. This is exactly why high-stakes funnels prefer postbacks.

How this works in LimeliJourney

Never hand-write the URL. LimeliJourney's tracking generates the exact snippet — open Tracking Links, pick the offer and event, and copy the image, URL, iframe, and server-to-server variants with the IDs baked in. Amber tokens like CLICK_ID and TRANSACTION_ID are placeholders you replace; green values are already set. Always fire at your own tracking domain, send a txn for deduplication, and check the Pixel Log — every fire, credited or not, appears there with the exact reason.