# Preferences.jl persistency on package update?

**URL:** <https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210>\
**Category:** General Usage\
**Tags:** preferences\
**Created:** [February 23, 2025, 12:15pm UTC](https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210 "2025-02-23T12:15:01Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Eben60](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/eben60/32/13475_2.png) [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Post date:** [February 23, 2025, 12:15pm UTC](https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210/1 "2025-02-23T12:15:01Z")

</div>

By default, preferences created by Preferences.jl are saved next to the Project.toml file of this package.

To my understanding, on an update of a package `Foo`, a new folder is created - e.g. the old version was in `.../packages/Foo/4iQz5/` , whereas the new one will be put into `.../packages/Foo/hJ0Fz/` .

Does that mean the preferences created under the old version of the package are not available under the updated version?

---

<div class="post-metadata">

**Author:** ![cjdoris](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cjdoris/32/213133_2.png) [@cjdoris](https://discourse.julialang.org/u/cjdoris)\
**Post date:** [February 23, 2025, 5:16pm UTC](https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210/2 "2025-02-23T17:16:01Z")

</div>

> [@Eben60](#):
>
> Does that mean the preferences created under the old version of the package are not available under the updated version?

No, preferences get stored in your current active project (such as `~/.julia/environments/v1.11/` or wherever) not in the installed package’s project, and therefore persist across package upgrades.

---

<div class="post-metadata">

**Author:** ![Eben60](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/eben60/32/13475_2.png) [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Post date:** [February 23, 2025, 5:28pm UTC](https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210/3 "2025-02-23T17:28:42Z")

</div>

Do I understand it correctly - if there is `MyProject.jl`, which is using package `Foo`, and that package `Foo` saves it’s preferences - those will be saved next to `Project.toml` of `MyProject.jl`?

---

<div class="post-metadata">

**Author:** ![cjdoris](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cjdoris/32/213133_2.png) [@cjdoris](https://discourse.julialang.org/u/cjdoris)\
**Post date:** [February 23, 2025, 5:30pm UTC](https://discourse.julialang.org/t/preferences-jl-persistency-on-package-update/126210/4 "2025-02-23T17:30:03Z")

</div>

Yep.