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PokeRadar
Forum-Index → Help → Answered → PokeRadarThe chances of hatching a shiny before 40 eggs is < 0.1%
The chances of hatching a shiny afterwards max out at 1.25%. The chain will break after a shiny is hatched or a Pokemon species different to the one being chained is hatched (that counts towards your chain).
For Premium users:
Similar to Normal users, only after hatching 40 eggs, the chances of hatching a shiny is raised to 2.5%.
Read more here: Pokeheroes Wiki