The chance of Magikarp being Shiny is not yet known, but early research suggested 1 in 400. In the original games, Shiny Pokémon chance was determined by several factors:

From Generation III onwards, shiny Pokémon are determined by other factors such as the Trainer ID number and the personality value of the Pokémon. Despite this change, the odds of randomly encountering a shiny Pokémon is still 1 in 8192. – Source

There is no confirmation how rare a Shiny Pokémon is in Pokémon GO, but early research suggested that the chance of a Shiny Magikarp was 1 in 400 during the Water Festival event.

When Niantic releases more Shiny Pokémon, we’ll have more information and accurate values.

  • eMike

    Almost 300 karps during event and 0 shiny!

  • Luca Sigala

    Almost 1000 karps and 0 shiny here. Same for my entire community..

  • Pamela Nizlak

    I caught 2 shiny magikarp within 30minutes of each other in the same place. My husband caught one on the first and his first magikarp and then his second one a few days later.

    • Xone

      I’ve yet to find a shiny, but if they are anything like Dittos or IV variables, then they are carbon-copy spawns.

      Example 1: you catch a specific spawn that turns into a Ditto. Anyone else who captures that same specific spawn will also obtain a Ditto.

      Example 2: You catch a specific spawn (of any kind including Dittos) anyone else who captures that same spawn will have the same IV results.

      This isn’t account specific either. You can switch accounts and the CP will vary but the IV and whether it’s a Ditto or not will remain the same.

  • Pascal F

    Zero in around 600 for me

  • Heydavid17

    I was so happy, that I got my one and only shiny, about 1 hour before the end of the event.

  • Pascal F

    Finally caught one today, very poor: 36 CP and 55% IV. won’t evolve it.

  • Higher_Ground

    been hoarding all my magikarp candy in hopes of getting a shiny. I’ve only caught 122 so far so I guess it might be awhile.

    But on a brighter note, I did catch a shiny Gastrodon in Pokémon Moon yesterday, so it’s not all bad. It’s only the 2nd shiny I’ve caught (first was a Bagon :P) but I was a little disappointed that it’s so similar to the normal version. So much so that I had to double check the summary to make sure I wasn’t just seeing stars when it appeared.