STOCK-BASED COMPENSATION - 2024 incentive award plan (Details) - The GRAIL, Inc. 2024 Incentive Award Plan - shares	Jan. 01, 2025	Sep. 30, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Additional shares authorized (in shares)	1,694,670
Number of shares authorized (in shares)	10,351,487
Shares available for grant (in shares)		481,705

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

GRAIL, Inc. 10-Q