A new Jackpot.win RTP study comparing 100 of the most popular online slots has revealed significant differences between casino operators, with Coolbet once again finishing top of the rankings.
The comparison analysed 100 widely played slots from developers including Pragmatic Play, Play’n GO, Hacksaw Gaming, Nolimit City, Relax Gaming and Blueprint. RTP values were collected directly from operators and compared across the same games wherever available.
After averaging the RTPs across all 100 slots, Coolbet emerged as the clear winner with an average RTP of 96.32%.
Average RTP Ranking
| Rank | Operator | Average RTP |
|---|---|---|
| 1 | Coolbet | 96.32% |
| 2 | UnionBet | 94.84% |
| 3 | GOATZ | 94.82% |
| 4 | ComeOn! | 94.64% |
| 5 | Unibet | 94.59% |
| 6 | Betsson | 94.51% |
| 7 | Epicbet | 94.50% |
| 8 | Respin | 94.50% |
| 9 | Casino Friday | 93.98% |
| — | Norsk Tipping* | 95.51% |
* Norsk Tipping recorded an average RTP of 95.51%, but offered only 15 of the 100 analysed slots and was therefore excluded from the main ranking.
A Clear Winner Across a Much Larger Sample
While the margins between several operators were relatively small, the gap between first and last place was substantial.
Coolbet’s average RTP of 96.32% was 2.34 percentage points higher than Casino Friday’s 93.98%.
That might not sound dramatic at first glance, but RTP differences compound over time and across thousands of spins. As our previous investigation demonstrated, even seemingly modest RTP reductions can translate into very large amounts of money being retained by operators rather than returned to players.
Readers interested in the financial impact of RTP reductions can read our earlier analysis:
The 100-slot RTP Report
The Biggest RTP Differences
The overall ranking only tells part of the story. While some slots were configured similarly across operators, others showed dramatic RTP reductions depending on where they were played.
Several games displayed gaps of multiple percentage points between the highest and lowest available RTP versions. In practical terms, that means two players could be playing exactly the same slot while receiving very different long-term returns.
Among the most striking examples were:
| Slot | Highest RTP | Lowest RTP | RTP Gap |
|---|---|---|---|
| Mystery Joker | 96.98% — Coolbet | 90.98% — Casino Friday | 6.00% |
| Legacy of Dead | 96.58% — Coolbet | 91.51% — Casino Friday | 5.07% |
| Moon Princess: 100 | 96.20% — Coolbet | 91.20% — Casino Friday | 5.00% |
| Book of Dead | 96.21% — Coolbet | 91.25% — Casino Friday | 4.96% |
| Le Bandit | 96.40% — Coolbet | 92.29% — Casino Friday | 4.11% |
| Undead Fortune | 96.42% — Coolbet | 92.33% — Casino Friday | 4.09% |
| Densho | 96.40% — Coolbet | 92.33% — Casino Friday | 4.07% |
| Frank’s Farm | 96.39% — Coolbet | 92.33% — Casino Friday | 4.06% |
| Cursed Seas | 96.33% — Coolbet | 92.29% — Casino Friday | 4.04% |
| Temple of Torment | 96.43% — Coolbet | 92.40% — Casino Friday | 4.03% |
The most dramatic example was Mystery Joker, where the gap between the highest and lowest RTP version was a full 6.00 percentage points. Several other titles, including Legacy of Dead, Moon Princess: 100 and Book of Dead, showed gaps of around five percentage points.
Jackpot.win has previously examined what RTP differences can mean in monetary terms. Read more in our analysis: The RTP Gap: Returning €37.96m More to Players.
These examples underline why players should pay attention not only to which slot they choose, but also where they choose to play it.
Catalogue Size Matters Too
The study also highlighted another important factor: game availability. Some operators may offer competitive RTPs on selected titles but provide access to a much smaller catalogue overall. Norsk Tipping is a good example. While its average RTP was high, it only offered 15 of the 100 slots included in this comparison.
For players looking to maximise value, both RTP and game selection matter. A strong RTP on a handful of games is useful, but a large catalogue gives players more opportunities to find favourable versions of popular slots.
Conclusion
The results of Jackpot.win’s largest RTP study to date reinforce a trend we have observed in previous investigations.
Coolbet once again delivered the highest average RTP in the comparison, while several competitors offered noticeably lower RTP configurations across the same games.
The study also shows why RTP remains one of the most important – and most overlooked – factors when choosing an online casino. Two operators may offer the same slot, but the long-term return can be very different.
For players who care about value, checking RTP before playing remains one of the simplest ways to improve their chances over time.