Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2025	Mar. 12, 2026
Document Information Line Items
Entity Central Index Key	0001844417
Document Type	10-K/A
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2025
Document Fiscal Year Focus	2025
Document Transition Report	false
Entity File Number	001-40608
Entity Registrant Name	ESTRELLA IMMUNOPHARMA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-1314502
Entity Address, Address Line One	5858 Horton Street
Entity Address, Address Line Two	Suite 370
Entity Address, City or Town	Emeryville
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94608
City Area Code	(510)
Local Phone Number	318-9098
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float		$ 20,496,203
Entity Common Stock, Shares Outstanding		42,665,228
Auditor Name	Macias Gini & O’Connell LLP
Auditor Location	Walnut Creek, CA
Auditor Firm ID	324
Amendment Description	Estrella Immunopharma, Inc. (“Estrella,” the “Company,” “we,” “our” or “us”) is filing this Amendment No. 1 on Form 10-K/A (this “Amendment”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (“Fiscal 2025”), as filed with the Securities and Exchange Commission (the “SEC”) on March 18, 2026 (the “Original Form 10-K”).The purpose of this Amendment is solely to disclose the information required in Part III (Items 10, 11, 12, 13 and 14) of Form 10-K, which information was previously omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K. Accordingly, we hereby amend and restate in its entirety Part III of the Original Form 10-K.In addition, pursuant to the rules of the SEC, Item 15 of Part IV has been amended and restated in its entirety to include the currently dated certifications of the Company’s principal executive officer and principal financial officer required under Section 302 of the Sarbanes-Oxley Act of 2002. Because no financial statements have been included in this Amendment and this Amendment does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4 and 5 of the certifications have been omitted. In addition, this Amendment does not include the certificate under Section 906 of the Sarbanes-Oxley Act of 2002 as no financial statements are being filed with this Amendment.Except as described above or as otherwise expressly provided by the terms of this Amendment, no other changes have been made to the Original Form 10-K. Except as otherwise indicated herein, this Amendment continues to speak as of the date of the Original Form 10-K, and we have not updated the disclosure contained therein to reflect any events that occurred subsequent to the filing date of the Original Form 10-K. This Amendment should be read in conjunction with the Original Form 10-K and with our filings with the SEC subsequent to the filing date of the Original Form 10-K.
Amendment Flag	true
Document Fiscal Period Focus	FY
Common Stock, par value $0.0001 per share
Document Information Line Items
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	ESLA
Security Exchange Name	NASDAQ
Warrants, each whole warrant exercisable for one share of Common Stock at an exercise price of $11.50
Document Information Line Items
Title of 12(b) Security	Warrants, each warrant exercisable for one share of Common Stock, each at an exercise price of $11.50 per share
Trading Symbol	ESLAW
Security Exchange Name	NASDAQ

Estrella Immunopharma, Inc. 10-K/A