    <SEC-DOCUMENT>0000950170-24-042066-index.html : 20240405
    <SEC-HEADER>0000950170-24-042066.hdr.sgml : 20240405
    <ACCEPTANCE-DATETIME>20240405083124
    ACCESSION NUMBER:		0000950170-24-042066
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		30
    CONFORMED PERIOD OF REPORT:	20240405
    FILED AS OF DATE:		20240405
    DATE AS OF CHANGE:		20240405

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ONTO INNOVATION INC.
    		CENTRAL INDEX KEY:			0000704532
    		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
    		ORGANIZATION NAME:           	08 Industrial Applications and Services
    		IRS NUMBER:				942276314
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1226

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-39110
    		FILM NUMBER:		24824838

    	BUSINESS ADDRESS:
    		STREET 1:		16 JONSPIN ROAD
    		CITY:			WILMINGTON
    		STATE:			MA
    		ZIP:			01887
    		BUSINESS PHONE:		9782536200

    	MAIL ADDRESS:
    		STREET 1:		16 JONSPIN ROAD
    		CITY:			WILMINGTON
    		STATE:			MA
    		ZIP:			01887

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	Onto Innovation Inc.
    		DATE OF NAME CHANGE:	20191025

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NANOMETRICS INC
    		DATE OF NAME CHANGE:	19920703
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEF 14A
    <SEQUENCE>1
    <FILENAME>onto-20240404.htm
    <DESCRIPTION>DEF 14A
    <TEXT>
    Document 1 - file: onto-20240404.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>img168886235_0.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: img168886235_0.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>img168886235_1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: img168886235_1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>img168886235_2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: img168886235_2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>img168886235_3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: img168886235_3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>img168886235_4.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: img168886235_4.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>img168886235_5.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: img168886235_5.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>img168886235_6.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: img168886235_6.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>img168886235_7.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: img168886235_7.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>img168886235_8.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: img168886235_8.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>img168886235_9.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: img168886235_9.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>img168886235_10.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: img168886235_10.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>img168886235_11.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: img168886235_11.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>img168886235_12.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: img168886235_12.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>img168886235_13.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: img168886235_13.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>img168886235_14.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: img168886235_14.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>img168886235_15.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: img168886235_15.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>img168886235_16.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: img168886235_16.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>img168886235_17.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: img168886235_17.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>img168886235_18.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: img168886235_18.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>21
    <FILENAME>onto-20240404.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA WITH EMBEDDED LINKBASES DOCUMENT
    <TEXT>
    Document 21 - file: onto-20240404.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>23
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 23 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>24
    <FILENAME>R2.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 24 - file: R2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>25
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 25 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>26
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 26 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>28
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 28 - file: FilingSummary.html

    Document 28 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>31
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 31 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>32
    <FILENAME>0000950170-24-042066-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 32 - file: 0000950170-24-042066-xbrl.zip

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>34
    <FILENAME>onto-20240404_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 34 - file: onto-20240404_htm.html

    Document 34 - RAW XML: onto-20240404_htm.xml

    </DOCUMENT>
    </SEC-DOCUMENT>