Conversion Window vs. Lookback Window: Understanding the Difference

These two terms are frequently confused, but they serve different purposes. Understanding the difference is essential for configuring offline conversion tracking correctly.

Quick Comparison

	Conversion Window	Lookback Window
Also called	Attribution window	Upload window
Configurable?	✅ Yes (1-90 days)	❌ No (platform-fixed)
Purpose	How long a conversion COUNTS	How long you CAN UPLOAD
Set where	Conversion action settings	Platform-enforced
Affects	Campaign attribution/reports	Upload acceptance

The Conversion Window (Attribution Window)

The conversion window defines how long after a click a conversion counts toward campaign performance and Smart Bidding.

In Google Ads

1. Goals → Conversions → your action → Edit settings
2. Click-through conversion window: 1, 7, 14, 30, 60, or 90 days

Example

Setting: 30-day conversion window
Click date: April 1

Conversion on April 15 → ✅ Attributed (within 30 days)
Conversion on April 25 → ✅ Attributed (within 30 days)
Conversion on May 5   → ❌ NOT attributed (35 days, outside window)

The Lookback Window (Upload Window)

The lookback window is the maximum time after a click that the platform will accept your uploaded conversion.

By Platform

Platform	Lookback Window	Configurable?
Google Ads (GCLID)	90 days	❌ No
Google Ads (ECL)	63 days	❌ No
Meta (CAPI)	7 days	❌ No
Microsoft Ads	90 days	❌ No
TikTok	28 days	❌ No

Example

Google Ads GCLID lookback: 90 days
Click date: April 1

Upload on April 15 → ✅ Accepted (14 days, within 90)
Upload on June 15  → ✅ Accepted (75 days, within 90)
Upload on July 5   → ❌ Rejected: EXPIRED_GCLID (95 days, outside 90)

How They Work Together

←————————————— Lookback Window (90 days) ——————————————→
←——— Conversion Window (30 days) ———→

Day 0        Day 30                                Day 90
|______________|__________________________________|
  Counts in     Accepted by platform              GCLID expires
  reports/bidding but NOT counted in reports

The Overlap Zone (Day 31-90)

Between day 31 and day 90:

• ✅ You CAN upload the conversion (within lookback window)
• ❌ It WON’T count in “Conversions” (outside attribution window)
• ⚠️ It WILL appear in “All conversions” (Google tracks it but doesn’t use for bidding)

This is why your conversion window should match your sales cycle. If your sales cycle is 45 days, set the conversion window to 60 days.

Configuration Recommendations

Business Type	Avg Sales Cycle	Conversion Window	Within Lookback?
Emergency services	0-1 day	7 days	✅ All platforms
HVAC repair	1-7 days	14 days	✅ All platforms
HVAC installation	7-30 days	30 days	✅ All platforms
Roofing	14-60 days	60 days	✅ Google/MS, ❌ Meta/TikTok
Legal	30-180 days	90 days	⚠️ Google/MS only

How TUOCA Handles Both Windows

1. Lookback validation — TUOCA checks each record against the platform’s lookback window before uploading
2. Expiration warnings — Records approaching the window limit are flagged
3. Priority routing — Meta uploads prioritized due to 7-day window
4. Attribution alignment — Recommends conversion window settings based on your sales cycle data