Document and Entity Information Document Information [Table] Class of Stock [Axis] Class of Stock [Domain] Common Stock [Member] Common Stock Ordinary shares Common Class A [Member] Class A Class A ordinary shares Common Class B [Member] Class B Class B ordinary shares ADR [Member] ADS Entity Addresses, Address Type [Axis] Address Type [Domain] Business Contact Document Information [Line Items] Document and Entity Information Document Type Document Registration Statement Document Annual Report Document Period End Date Current Fiscal Year End Date Document Fiscal Year Focus Document Transition Report Document Shell Company Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Three Entity Address, City or Town Entity Address, Postal Zip Code Entity Address, Country Contact Personnel Name Contact Personnel Email Address Country Region City Area Code Local Phone Number Title of 12(g) Security Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Emerging Growth Company Document Accounting Standard Entity Shell Company Entity Central Index Key Document Fiscal Period Focus Amendment Flag ICFR Auditor Attestation Flag Document Financial Statement Error Correction [Flag] Auditor Name Auditor Firm ID Auditor Location CONSOLIDATED BALANCE SHEETS Statement [Table] Statement [Line Items] Statement Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Restricted Cash and Cash Equivalents, Current Restricted cash Accounts Receivable, Net, Current Accounts receivable, net of allowance for credit losses of US$89,130 and US$49,916 as of December 31, 2024 and 2025, respectively Accounts receivable, net Accounts receivable, net Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Prepaid expenses and other current assets Prepaid expense and other assets Assets, Current Total current assets Property, plant and equipment - net Property and equipment, net Property and equipment, net Property and equipment, net Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Long-term Investments. Long-term investments Carrying amount of long term investment Other Assets, Noncurrent Other non-current assets Assets TOTAL ASSETS Liabilities and Equity [Abstract] LIABILITIES AND SHAREHOLDERS' DEFICIT Liabilities, Current [Abstract] Current liabilities (including amounts of the consolidated VIEs without recourse to the Company. See Note 2(b)): Current liabilities: Accounts Payable, Current Accounts payable Accounts payable Short-term Debt Outstanding balance of working capital loan Short-term borrowings Employee-related Liabilities, Current Accrued salary and benefits Operating Lease, Liability, Current Less: Operating lease liabilities, current Operating lease liabilities, current Amount of obligations incurred and payable, pertaining to costs that are statutory in nature, incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include, but not limited to, taxes, interest, rent and utilities. Also includes the aggregate carrying amount of liabilities not separately disclosed. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Accrued Expenses And Other Current Liabilities. Accrued expenses and other current liabilities Total Accrued expenses and other current liabilities Deferred Revenue, Current Deferred revenue Liabilities, Current Total current liabilities Operating Lease, Liability, Noncurrent Operating lease liabilities, non-current Long-term operating lease liabilities Liabilities TOTAL LIABILITIES Commitments and Contingencies. Commitments and contingencies Equity, Attributable to Parent [Abstract] Shareholders' deficit: SHAREHOLDERS' DEFICIT: Common Stock, Value, Issued Ordinary shares Ordinary shares Additional Paid in Capital Additional paid-in capital Retained Earnings (Accumulated Deficit) Accumulated deficit Accumulated deficit Aggregate accumulated deficit Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Accumulated other comprehensive loss Stockholders' Equity Attributable to Parent Ending balance Beginning balance Total shareholders' deficit Total shareholders' deficit Liabilities and Equity TOTAL LIABILITIES AND SHAREHOLDERS' (DEFICIT)/ EQUITY TOTAL LIABILITIES AND SHAREHOLDERS' DEFICIT Allowance for Doubtful Accounts Receivable, Current Balance at end of the year Balance at beginning of the year Allowance for credit losses Common Stock, Par or Stated Value Per Share Ordinary shares, par value Common Stock, Shares Authorized Ordinary shares, shares authorized Common Stock, Shares, Issued Ordinary shares, shares issued Common Stock, Shares, Outstanding Ending balance (in shares) Beginning balance (in shares) Ordinary shares, shares outstanding CONSOLIDATED STATEMENTS OF OPERATIONS Products and Services [Axis] Products and Services [Domain] Represents information pertaining to In-app purchase revenue. In-App Purchase [Member] In-app purchase revenues Advertising revenue Advertising revenue Other revenue Other revenues Revenues Net revenues Net revenues Cost of revenue. Cost of revenues (including share-based compensation expense of US$21,434, US$20,456 and US$8,160 in 2023, 2024 and 2025, respectively) Cost of revenues Gross Profit Gross profit Operating Expenses [Abstract] Operating expenses: General and Administrative Expense General and administrative expenses (including share-based compensation expense of US$512,837, US$53,290 and US$5,532 in 2023, 2024 and 2025, respectively) General and administrative expenses Research and Development Expense Research and development expenses (including share-based compensation expense of US$180,355, US$60,297 and US$24,033 in 2023, 2024 and 2025, respectively) Research and development expenses Selling and Marketing Expense Sales and marketing expenses (including share-based compensation expense of US$(10,061), US$517 and nil in 2023, 2024 and 2025, respectively) Sales and marketing expenses Other Operating Income (Expense), Net Other operating income, net Total Other operating income, net Operating Expenses Total operating expenses Operating Income (Loss) Loss from operations (Loss) income from operations Income from operations Interest Income (Expense), Nonoperating, Net Interest (expenses) income, net Interest expenses, net Foreign Currency Transaction Gain (Loss), before Tax Foreign exchange (loss) gain, net Foreign exchange gains (losses), net Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (loss) before income taxes Income (loss) before income taxes Loss before income taxes and equity in earnings of subsidiaries Income Tax Expense (Benefit) Income tax expenses Income tax expense Income tax expense Net (loss) income Net (loss) income Net Income (Loss) Available to Common Stockholders, Basic Net (loss) income attributable to ordinary shareholders Earnings Per Share Reconciliation [Abstract] Net (loss) income per ordinary share: Earnings Per Share, Basic Basic (in dollars per share) Net income (loss) per share, basic (in dollars per share) Earnings Per Share, Diluted Diluted (in dollars per share) Net income (loss) per share, diluted (in dollars per share) Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted average shares used in calculating net loss per ordinary share: Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Weighted average number of ordinary shares outstanding, Diluted (in shares) Income Statement Location [Axis] Income Statement Location [Domain] Cost of sales Cost of revenue General and Administrative Expense [Member] General and administrative expenses Research and Development Expense [Member] Research and development expenses Selling and Marketing Expense [Member] Sales and marketing expenses Allocated Share-based Compensation Expense Share-based compensation expense Entity Listing, Depository Receipt Ratio ADS ratio CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive (loss) income Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation adjustments, net of tax of nil Foreign currency translation adjustments Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive (loss) income attributable to CooTek (Cayman) Inc. Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to ordinary stockholder of parent entity. Comprehensive Income (Loss), Net of Tax, Attributable to Ordinary Stockholders Total comprehensive (loss) income attributable to ordinary shares of CooTek (Cayman) Inc. Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Foreign currency translation adjustments, tax CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (DEFICIT) Equity Components [Axis] Equity Component [Domain] Additional paid-in capital [Member] Additional paid-in capital Retained Earnings [Member] Accumulated deficit Accumulated Other Comprehensive (loss) income [Member] Accumulated other comprehensive (loss) income Increase (Decrease) in Stockholders' Equity [Roll Forward] CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Share-based compensation CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Cash flows from operating activities: Operating activities: Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net (loss) income Net (loss) income Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Adjustment to reconcile net loss to net cash provided by (used in) operating activities: Depreciation, Depletion and Amortization Depreciation and amortization A valuation allowance for trade and other receivables due to an Entity that are expected to be uncollectible. Provision For Allowance Of Doubtful Accounts Provision (reversal) for credit losses Share-based Compensation. Share-based compensation expense Share-based compensation Amortization of Debt Issuance Costs and Discounts Amortization of issuance cost and debt discounts related to convertible notes Gain (Loss) on Disposition of Property Plant Equipment Gain on disposal of property and equipment Gain on disposal of property and equipment The amount of non cash lease expenses. Non Cash Lease Expense Noncash lease expense Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities: Changes in assets and liabilities: Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other current assets Increase (Decrease) in Other Noncurrent Assets Other non-current assets Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Employee Related Liabilities Accrued salary and benefits Increase (Decrease) in Other Accrued Liabilities Accrued expenses and other current liabilities The increase (decrease) during the reporting period in operating lease liabilities. Increase (Decrease) in Operating Lease Liabilities Operating lease liabilities Increase (Decrease) in Customer Advances Deferred revenue Increase (Decrease) in Other Noncurrent Liabilities Other non-current liabilities Net Cash Provided by (Used in) Operating Activities Net cash (used in) provided by operating activities Net cash used in operating activities Net cash used in operating activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Cash flows from investing activities: Investing activities: Payments to Acquire Productive Assets Purchases of property and equipment and intangible assets Proceeds from Sale of Productive Assets Proceeds from disposal of property and equipment Proceeds from Sale, Maturity and Collection of Short-term Investments Proceeds from reclaim of short-term investments Proceeds from Sale, Maturity and Collection of Long-Term Investments Proceeds from reclaim of long-term investments Net Cash Provided by (Used in) Investing Activities Net cash provided by investing activities Net cash provided by (used in) investing activities Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Cash flows from financing activities: Financing activities: Proceeds from Short-term Debt Proceeds from short-term borrowings Repayments of Short-term Debt Repayment of short-term borrowings Repayments of Convertible Debt Repayment of convertible notes Redeem the loan principle, redemption premium and unpaid interests Net Cash Provided by (Used in) Financing Activities Net cash (used in) provided by financing activities Net cash (used in) provided by financing activities Net cash (used in) provided by financing activities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Net (decrease) increase in cash, cash equivalents and restricted cash Net (decrease) increase in cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents, and restricted cash at end of year Cash, cash equivalents, and restricted cash at beginning of year The Group's cash and cash equivalents and restricted cash Total cash, cash equivalents, and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Effect of exchange rate changes on cash, cash equivalents and restricted cash Supplemental disclosure of non-cash investing and financing activities: Supplemental disclosure of cash flow information: The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes. Income Tax Paid Income taxes paid Interest Paid, Excluding Capitalized Interest, Operating Activities Interest paid The amount of cash paid for amounts included in the measurement of operating lease liabilities. Cash Paid For Amounts Included In The Measurement Of Operating Lease Liabilities Cash paid for amounts included in the measurement of operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Operating lease right-of-use assets obtained in exchange for operating lease liabilities Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] Reconciliation in amounts on consolidated balance sheets: Restricted Cash and Cash Equivalents Restricted cash Organization and Principal Activities Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Principal Activities Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Summary of Significant Accounting Policies Accounts Receivable, net Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Accounts Receivable, net Prepaid Expenses and Other Current Assets The entire disclosure about prepaid expenses and other current assets. Prepaid Expenses and Other Current Assets [Text Block] Prepaid Expenses and Other Current Assets Property and Equipment, net Property, Plant and Equipment Disclosure [Text Block] Property and Equipment, net Intangible Assets, net Intangible Assets Disclosure [Text Block] Intangible Assets, net