From Static Hermes to Hermes V1: The Road to Default

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Guest
Nicola Corti
React Native Team
@
Meta

The "Static Hermes" codename is gone, replaced by the official release of Hermes V1. Nicola Corti (Meta) explains that for two years, the team's explorations of static typing benefits lived on a separate branch, with many performance boosts never shipping to users.

Now, Hermes V1 is here (and experimental in RN 0.82), shipping those performance improvements. It is not yet the default; React Native 0.82 pre-builds against the stable Hermes, so developers must enable "build from source" to try V1, which will result in slower build times. This temporary step is necessary to gather feedback from large apps.

Nicola also clarifies that while Hermes V1 will natively support methods like Set and Map (removing the need for polyfills), the real benefits come from the new performance foundation. He expects V1 to become the stable, default engine in two or three releases, projected for early 2026.

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