XML 72 R45.htm IDEA: XBRL DOCUMENT
v3.25.0.1

REVENUE - Narrative (Details) | 12 Months Ended
--- | ---
Dec. 31, 2024 revenueSource user | Dec. 31, 2023 | Dec. 31, 2022
Disaggregation of Revenue [Line Items] |  |  |
Number of sources of revenue | revenueSource | 4 |  |
Number of users | user | 6 |  |
Number of hours to make certification decision (less than) | 48 hours |  |
Number of days to take exam | 21 days |  |
Expiration period to take exams (in years) | 1 year |  |
Maximum |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Subscription period (in years) | 1 year |  |
Revenue from Contract with Customer Benchmark | Geographic Concentration Risk | United States |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Concentration risk (in percent) | 42.00% | 45.00% | 46.00%
Apple | Revenue from Contract with Customer Benchmark | Customer Concentration Risk |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Concentration risk (in percent) | 60.80% | 58.50% | 54.20%
Google | Revenue from Contract with Customer Benchmark | Customer Concentration Risk |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Concentration risk (in percent) | 23.40% | 25.60% | 28.10%
Stripe | Revenue from Contract with Customer Benchmark | Customer Concentration Risk |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Concentration risk (in percent) | 11.70% | 12.10% |

X
- Definition Contract With Customer, Certification Period Prior To Test Completion + References No definition available. + Details
Name: | duol_ContractWithCustomerCertificationPeriodPriorToTestCompletion
Namespace Prefix: | duol_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contract With Customer, Number Of Users Per Subscription + References No definition available. + Details
Name: | duol_ContractWithCustomerNumberOfUsersPerSubscription
Namespace Prefix: | duol_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contract With Customer, Threshold Period To Take Exam For Bulk Purchase + References No definition available. + Details
Name: | duol_ContractWithCustomerThresholdPeriodToTakeExamForBulkPurchase
Namespace Prefix: | duol_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contract With Customer, Threshold To Take Exam + References No definition available. + Details
Name: | duol_ContractWithCustomerThresholdToTakeExam
Namespace Prefix: | duol_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number Of Sources Of Revenue + References No definition available. + Details
Name: | duol_NumberOfSourcesOfRevenue
Namespace Prefix: | duol_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-42 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-21 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-20 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-18 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-20 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-5 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 + Details
Name: | us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b)(1) -SubTopic 10 -Topic 606 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-13 + Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_RevenueFromContractWithCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_GeographicConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=duol_AppleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=duol_GoogleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=duol_StripeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |