| Document And Entity Information | Dec. 01, 2020 |
| Document Information [Line Items] | |
| Entity, Registrant Name | PDF SOLUTIONS, INC. |
| Document, Type | 8-K |
| Document, Period End Date | Dec. 1, 2020 |
| Entity, File Number | 000-31311 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, Tax Identification Number | 25-1701361 |
| Entity, Address, Address Line One | 2858 De La Cruz Boulevard |
| Entity, Address, City or Town | Santa Clara |
| Entity, Address, State or Province | CA |
| Entity, Address, Postal Zip Code | 95050 |
| City Area Code | 408 |
| Local Phone Number | 280-7900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | PDFS |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001120914 |
