Task ID returned from the API has changed?

Materials Project
1

Hi, task ID returned in JSON is only letters now, instead of numbers:

{"data": [{"formula_pretty": "Fe2O3", "material_id": "mp-aaaaacea",

When copied in the browser it redirects to the numerical ID:

https://next-gen.materialsproject.org/materials/mp-aaaaacea

mp-1456. Is it intentional? Can we get back numerical IDs?

Thanks.

2

Hi Sasha,

This was an intentional change made in our database release v2026.04.13. This decision was made primarily because the Material and Task ID namespaces were becoming increasingly conflated - moving Materials to AlphaID creates a clear distinction between the two. Additionally, AlphaIDs are sortable, more memorable, and more easily extensible as identifiers.

To convert between the AlphaID (new format) and the Numeric ID (old format), it’s a base conversion from base-26 to base-10.

You can read more about this in our documentation.

3

Thanks for a fast reply, very helpful.

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