Basis of Presentation	9 Months Ended
Sep. 27, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	NOTE 1. Basis of Presentation The accompanying interim unaudited Condensed Consolidated Financial Statements have been prepared by Onto Innovation Inc. (together with its consolidated subsidiaries, unless otherwise specified or suggested by the context, the “Company,” “Onto Innovation,” “we,” “our” or “us”) and in the opinion of management reflect all adjustments, consisting of normal recurring accruals, necessary for their fair presentation in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain reclassifications have been made to prior-period amounts to conform to current-period presentation. Preparing financial statements requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ materially from reported amounts. The interim results for the three and nine-month periods ended September 27, 2025 are not necessarily indicative of results to be expected for the entire year or any future periods. This interim financial information should be read in conjunction with the financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 28, 2024 (the “2024 Form 10-K”) filed with the Securities and Exchange Commission on February 25, 2025. The accompanying Condensed Consolidated Balance Sheet at December 28, 2024 has been derived from the audited consolidated financial statements included in the 2024 Form 10-K. The Company operates on a 52- or 53-week fiscal year ending on the Saturday closest to December 31. Our fiscal year ending January 3, 2026 (“fiscal year 2025”) is a 53-week fiscal year. The first quarter of the Company’s fiscal year 2025 ended on March 29, 2025, the second quarter ended on June 28, 2025 and the third quarter ended on September 27, 2025. Our fiscal year ended December 28, 2024 was a 52-week fiscal year. The third quarter of the fiscal year ended December 28, 2024 ended on September 28, 2024. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Estimates made by management include excess and obsolete inventory, fair value of assets acquired and liabilities assumed in a business combination, recoverability and useful lives of property, plant and equipment and identifiable intangible assets, recoverability of goodwill, recoverability of deferred tax assets, allowance for credit losses, liabilities for product warranty, share-based payments and liabilities for tax uncertainties. Actual results could differ from those estimates. These estimates and assumptions are based on historical experience and on various other factors which the Company believes to be reasonable under the circumstances. The Company may engage third-party valuation specialists to assist with estimates related to the valuation of financial instruments, assets and stock awards associated with various contractual arrangements. Such estimates often require the selection of appropriate valuation methodologies and significant judgment. Actual results could differ from these estimates under different assumptions or circumstances and such differences could be material. Recent Accounting Pronouncements Updates Not Yet Effective In September 2025, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2025-06, Intangibles-Goodwill and Other-Internal Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which removes all references to software development stages and clarifies the threshold entities apply to begin capitalizing costs. ASU No. 2025-06 is effective for annual periods beginning after December 15, 2027 and interim reporting periods within those annual reporting periods. The ASU may be applied prospectively, retrospectively or through a modified transition approach with early adoption permitted. The Company is currently evaluating the potential impact of this standard on its consolidated financial statements. In July 2025, the FASB issued ASU No. 2025-05, Financial Instruments - Credit Losses (Topic 326), which simplifies the estimation of credit losses on current accounts receivable and current contract assets arising from transactions accounted for under Accounting Standards Codification 606, Revenue from Contracts with Customers. The guidance allows all entities to use a practical expedient to assume that the current conditions as of the balance sheet date will remain unchanged for the remaining life of the asset when developing a reasonable and supportable forecast as part of estimating expected credit losses on these assets. The guidance is effective for fiscal years beginning after December 15, 2025, and interim periods within those fiscal years. Early adoption is permitted. Entities that elect the practical expedient are required to apply the amendments prospectively. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. Other than the standards listed above, there have been no recent accounting pronouncements or changes in accounting pronouncements during the three and nine months ended September 27, 2025, as compared to the recent accounting pronouncements described in the 2024 Form 10-K, that are of significance, or potential significance, to the Company.

Basis of Presentation

9 Months Ended

Sep. 27, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

NOTE 1. Basis of Presentation

The accompanying interim unaudited Condensed Consolidated Financial Statements have been prepared by Onto Innovation Inc. (together with its consolidated subsidiaries, unless otherwise specified or suggested by the context, the “Company,” “Onto Innovation,” “we,” “our” or “us”) and in the opinion of management reflect all adjustments, consisting of normal recurring accruals, necessary for their fair presentation in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain reclassifications have been made to prior-period amounts to conform to current-period presentation. Preparing financial statements requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ materially from reported amounts. The interim results for the three and nine-month periods ended September 27, 2025 are not necessarily indicative of results to be expected for the entire year or any future periods. This interim financial information should be read in conjunction with the financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 28, 2024 (the “2024 Form 10-K”) filed with the Securities and Exchange Commission on February 25, 2025. The accompanying Condensed Consolidated Balance Sheet at December 28, 2024 has been derived from the audited consolidated financial statements included in the 2024 Form 10-K.

The Company operates on a 52- or 53-week fiscal year ending on the Saturday closest to December 31. Our fiscal year ending January 3, 2026 (“fiscal year 2025”) is a 53-week fiscal year. The first quarter of the Company’s fiscal year 2025 ended on March 29, 2025, the second quarter ended on June 28, 2025 and the third quarter ended on September 27, 2025. Our fiscal year ended December 28, 2024 was a 52-week fiscal year. The third quarter of the fiscal year ended December 28, 2024 ended on September 28, 2024.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Estimates made by management include excess and obsolete inventory, fair value of assets acquired and liabilities assumed in a business combination, recoverability and useful lives of property, plant and equipment and identifiable intangible assets, recoverability of goodwill, recoverability of deferred tax assets, allowance for credit losses, liabilities for product warranty, share-based payments and liabilities for tax uncertainties. Actual results could differ from those estimates.

These estimates and assumptions are based on historical experience and on various other factors which the Company believes to be reasonable under the circumstances. The Company may engage third-party valuation specialists to assist with estimates related to the valuation of financial instruments, assets and stock awards associated with various contractual arrangements. Such estimates often require the selection of appropriate valuation methodologies and significant judgment. Actual results could differ from these estimates under different assumptions or circumstances and such differences could be material.

Recent Accounting Pronouncements

Updates Not Yet Effective

In September 2025, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2025-06, Intangibles-Goodwill and Other-Internal Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which removes all references to software development stages and clarifies the threshold entities apply to begin capitalizing costs. ASU No. 2025-06 is effective for annual periods beginning after December 15, 2027 and interim reporting periods within those annual reporting periods. The ASU may be applied prospectively, retrospectively or through a modified transition approach with early adoption permitted. The Company is currently evaluating the potential impact of this standard on its consolidated financial statements.

In July 2025, the FASB issued ASU No. 2025-05, Financial Instruments - Credit Losses (Topic 326), which simplifies the estimation of credit losses on current accounts receivable and current contract assets arising from transactions accounted for under Accounting Standards Codification 606, Revenue from Contracts with Customers. The guidance allows all entities to use a practical expedient to assume that the current conditions as of the balance sheet date will remain unchanged for the remaining life of the asset when developing a reasonable and supportable forecast as part of estimating expected credit losses on these assets. The guidance is effective for fiscal years beginning after December 15, 2025, and interim periods within those fiscal years. Early adoption is permitted. Entities that elect the practical expedient are required to apply the amendments prospectively. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements.

Other than the standards listed above, there have been no recent accounting pronouncements or changes in accounting pronouncements during the three and nine months ended September 27, 2025, as compared to the recent accounting pronouncements described in the 2024 Form 10-K, that are of significance, or potential significance, to the Company.