    <SEC-DOCUMENT>0001193125-26-186941-index.html : 20260428
    <SEC-HEADER>0001193125-26-186941.hdr.sgml : 20260428
    <ACCEPTANCE-DATETIME>20260428160602
    ACCESSION NUMBER:		0001193125-26-186941
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		2
    FILED AS OF DATE:		20260428
    DATE AS OF CHANGE:		20260428

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Alector, Inc.
    		CENTRAL INDEX KEY:			0001653087
    		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
    		ORGANIZATION NAME:           	03 Life Sciences
    		EIN:				822933343
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-38792
    		FILM NUMBER:		26907612

    	BUSINESS ADDRESS:
    		STREET 1:		131 OYSTER POINT BLVD., SUITE 600
    		CITY:			SOUTH SAN FRANCISCO
    		STATE:			CA
    		ZIP:			94080
    		BUSINESS PHONE:		415-231-5660

    	MAIL ADDRESS:
    		STREET 1:		131 OYSTER POINT BLVD., SUITE 600
    		CITY:			SOUTH SAN FRANCISCO
    		STATE:			CA
    		ZIP:			94080

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	Alector LLC
    		DATE OF NAME CHANGE:	20150915
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEFA14A
    <SEQUENCE>1
    <FILENAME>alec-20260422.htm
    <DESCRIPTION>DEFA14A
    <TEXT>
    Document 1 - file: alec-20260422.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>img214297469_0.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: img214297469_0.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>