Document and Entity Information
| Document and Entity Information | Jun. 10, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | IMPINJ INC |
| Amendment Flag | true |
| Entity Central Index Key | 0001114995 |
| Document Type | 8-K/A |
| Document Period End Date | Jun. 10, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-37824 |
| Entity Tax Identification Number | 91-2041398 |
| Entity Address, Address Line One | 400 Fairview Avenue North |
| Entity Address, Address Line Two | Suite 1200 |
| Entity Address, City or Town | Seattle |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98109 |
| City Area Code | (206) |
| Local Phone Number | 517-5300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.001 per share |
| Trading Symbol | PI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Amendment Description | On June 11, 2021, Impinj, Inc. filed a Current Report on Form 8-K (the “Original Report”) to report the voting results from its 2021 annual meeting of stockholders. This Current Report on Form 8-K/A is being filed to correct an error in the presentation of the results for the stockholder proposal considered at the meeting. For convenience of the reader, this filing restates the entire contents of the Original Report, with the only modification being the inclusion of the correct voting result on the shareholder proposal. |