A code claiming 50% off and a code claiming 10% off are not equally likely to survive your cart. This live data study sorts every tracked promo code by how deep its discount claims to be and reads each band against SimplyCodes' real checkout attempts, rebuilt every day as new attempts land.
Yes. As of August 19, 2026, promo codes claiming 1% to 10% off applied at 82.1% of real checkout attempts on SimplyCodes, while codes claiming 50% off or more applied at 59.3% — a 22.8-point drop measured across 10,789,248 checkout attempts on 699,156 codes at 33,504 stores.
- The shallowest codes are the most dependable: 1-10% off applied at 82.1% against 59.3% for 50% off or more, a 22.8-point gap.
- The gap is wider than the gap between retail categories, so the discount a code claims tells a shopper more about whether it will apply than the aisle it sits in.
- Every step down the ladder falls — each deeper band applied less often than the band above it, across all 5 bands.
Discount claimed = the percentage off the code states · Checkout success = the share of real checkout attempts on codes in that band where the code applied · Attempts = the count behind that share · Codes = distinct codes in the band · Stores = how many stores contributed.
| # | Discount claimed | Checkout success | Attempts | Codes | Stores |
|---|---|---|---|---|---|
| 1 | 1-10% off | 82.1% | 6,755,131 | 408,787 | 27,479 |
| 2 | 11-19% off | 77.7% | 2,030,193 | 131,075 | 19,308 |
| 3 | 20-29% off | 71.5% | 1,457,218 | 111,581 | 19,509 |
| 4 | 30-49% off | 64.3% | 381,271 | 32,732 | 9,130 |
| 5 | 50% off or more | 59.3% | 165,435 | 14,981 | 5,026 |
5 discount bands, in depth order rather than ranked by rate · an all-store aggregate, no individual store named or graded · the figure describes a band, never a store · checked August 20, 2026 · numbers last changed Aug 19, 2026. Refreshed daily.
More from this live data study
The ladder holds in every category measured
The drop is not an accident of which categories happen to write deep codes. Splitting the same checkout attempts by retail category, codes claiming 30% off or more applied less often than codes claiming 19% off or less in all 16 retail categories that carry enough attempts to split. The gap is narrowest in Electronics, where shallow codes applied at 75.6% against 72.7% for deep ones. It is widest in Business, at 85.0% against 41.2%.
That matters because the obvious objection to a market-wide ladder is composition — the worry that deep codes cluster in a few unreliable corners of retail and drag the band average down. They do not. The pattern repeats inside every corner.
Inside one store the penalty is small
Most of the market gap comes from which stores issue deep codes, not from the same store's deep code being much weaker than its shallow one. Of the 1,656 stores carrying both a shallow code and a deep one with at least 50 checkout attempts on each, 982 — 59.3% — show the deeper code applying less often. The median store's gap is 1.2 percentage points.
So depth reads as a signal about the offer and the store behind it. A seller that runs one deep promotion a year with a narrow product carve-out is a different kind of seller from one that keeps a standing welcome code current, and the ladder is largely measuring that difference. A deep code from a store whose codes usually work is still a good bet.
What "50% off" is worth at checkout
The round numbers shoppers search for do not behave alike. Codes claiming exactly 10% off applied at 82.4% of 5,325,634 checkout attempts. Codes claiming exactly 50% off applied at 48.7% of 79,665 attempts, which is under half.
In between, the fall is steady rather than smooth: 79.0% at 15% off, 73.3% at 20%, 66.8% at 25% and 64.0% at 30%, then a step back up to 65.7% at 40% off, measured on 90,509 attempts against 209,212 at 30%. Above 50% off, the codes at any single figure are too few to publish a rate for each step, which is why this live data study bands the deep end.
How to read a discount claim
Read the claimed discount as a probability, not a promise. If two codes would save you a similar amount — a shallow one on a full basket against a deep one on a single line item — take the shallower one first.
And check the store before you judge the code. Reliability is a property of the seller as much as the offer, and a deep code at a store that keeps its codes current behaves nothing like the same figure at a store that leaves old promotions listed.
Frequently asked questions
Do bigger discount codes work less often?
How does SimplyCodes measure promo code reliability by discount size?
How often is SimplyCodes' data on promo code reliability by discount size updated?
Which SimplyCodes categories should I browse after reading about promo code reliability by discount size?
Methodology
How SimplyCodes verifies codes. Behind every figure in this live data study is the SimplyCodes verification system. Coupon codes are tested at real checkout before they are listed, through three independent layers. Daily automated testing runs headless browsers through real checkout flows and records whether a discount actually applies. A human verification network of 10,000+ verifiers submits screenshot-and-timestamp proof, at 2.3M+ monthly code verifications and 98% accuracy. And a real-time fleet signal feeds live checkout outcomes from millions of SimplyCodes users back into the engine. Each code carries a Health Score from 0–100, weighted by checkout outcomes, verifier consensus, and recency. With an estimated 40–60% of coupon codes on the public web dead, restricted, or fake, the system exists so a code earns its place by working at checkout, not by being collected.
How this study is built. Checkout success is successes over total attempts at the latest cumulative snapshot, pooled across every source — the same definition the live reliability boards publish, so this live data study and those boards cannot contradict each other. Each attempt is matched back to the code record it belongs to, and the band comes from the percentage that code states. Stores with more than 500 codes in a month are dropped as data-quality outliers before counting. Percentage claims of 95% or more never enter the calculation. Sensitive retail verticals are excluded by category before any counting. Every figure describes a band of codes, never a store: no individual retailer is named or graded anywhere on this board. Figures refresh with the data snapshot shown above.
Cite this data
As of August 19, 2026, promo codes claiming 1% to 10% off applied at 82.1% of real checkout attempts on SimplyCodes against 59.3% for codes claiming 50% off or more — a 22.8-point drop across 10,789,248 attempts.
According to the SimplyCodes Discount Depth Reliability Study (August 19, 2026), promo-code checkout success falls 22.8 points from the shallowest discount band to the deepest, measured on 10,789,248 real checkout attempts.
