2026-2027 application cycle
Caltech Application Guide: Essays, Deadlines, and Requirements (2026-2027)
Caltech's Fall 2027 supplement asks about STEM interests, scholarly character, scientific drive, and community contribution. Restrictive Early Action is due November 1, 2026, and Regular Decision is due January 4, 2027. Caltech requires the SAT or ACT and publishes detailed ethical AI guidelines.
Current supplemental essay prompts and limits
The prompt descriptions below are concise planning summaries. Open the linked official source and confirm the exact wording in the live application before drafting.
STEM academic interest
Name one or two current areas of interest and explain why you chose them.
Limit: 150 to 200 words
Confirm on the official California Institute of Technology page
Scholarly character
Choose a collaboration or problem-solving process prompt to show how you learn when the answer is not easy.
Limit: Up to 200 words
Confirm on the official California Institute of Technology page
Scientific drive
Choose two prompts about a STEM learning rabbit hole, sustained pursuit, or something you made, tested, repaired, modeled, coded, built, or redesigned.
Limit: Two responses, up to 200 words each
Confirm on the official California Institute of Technology page
Community contribution
Describe something you would be excited to do, share, teach, make, start, or contribute at Caltech.
Limit: 100 to 150 words
Confirm on the official California Institute of Technology page
Official application requirements
- Common App or QuestBridge Application
- Caltech-specific questions
- SAT or ACT
- School and counselor materials
- Teacher recommendations
- English-proficiency testing where applicable
Deadlines and decision plans
Restrictive Early Action: November 1, 2026
Required materials are due November 6, and testing must be completed before November 30 under the published calendar.
Regular Decision: January 4, 2027
Required materials are due January 10, and testing must be completed before December 31 under the published calendar.
Testing policy
Caltech requires the SAT or ACT. ACT writing and science are not required. Applicants with AP or IB results are asked to submit those scores as well.
AI and authorship policy
Published policy found. Caltech permits brainstorming questions or exercises, grammar and spelling review of a completed essay, and application-process research. It prohibits AI-created outlines or drafts, replacement of the applicant's voice, and AI translation of an essay written in another language.
What the published guidance clearly permits
- Questions or exercises that start brainstorming
- Grammar and spelling review of a completed essay
- Research about the application process
What the published guidance prohibits
- AI-generated outlines or drafts
- Replacing the applicant's voice or tone
- AI translation of an essay written in another language
What remains uncertain
Caltech's examples are unusually specific, but they are not an exhaustive list of every tool behavior. Compare the actual action to the policy, not the product label.
A detector percentage is not a substitute for this policy. Preserve notes, dated drafts, revision history, and feedback so the development of the student's own work remains visible.
Get technical when the detail is yours
Caltech explicitly invites technical detail. Use it to show what held your attention, what failed, or what changed in your thinking. Technical vocabulary by itself is not reflection.
Keep process and outcome separate
The scholarly-character options focus on collaboration and process. Pick an episode where another person or a hard turn changed how you worked, then make the change visible instead of summarizing yourself as collaborative or persistent.
Common questions
What are the Caltech supplemental essay word limits?+
The current supplement includes a 150 to 200 word STEM-interest response, a scholarly-character response up to 200 words, two scientific-drive responses up to 200 words each, and a 100 to 150 word community response.
Can applicants use AI to brainstorm Caltech essays?+
Caltech's published guidelines permit questions or exercises that help start brainstorming. They prohibit AI-generated outlines and drafts.
Is Caltech test optional for Fall 2027?+
No. Caltech's official application requirements list the SAT or ACT as required.
Change notes
- Caltech labels the current page Fall 2027 and says its supplemental questions change annually.
- The deadlines page contains one inconsistent 2026 date in Regular Decision prose; this guide uses the internally consistent 2027 table and flags the discrepancy for applicants to recheck.
Official sources
These first-party pages were reviewed on 2026-08-11. Requirements can change during an application cycle.
- First-Year Application Requirements (Caltech Undergraduate Admissions)
- First-Year Application Deadlines (Caltech Undergraduate Admissions)
- Fall 2027 Supplemental Application Essays (Caltech Undergraduate Admissions)
- Standardized Tests (Caltech Undergraduate Admissions)
- Ethical Use of AI Guidelines (Caltech Undergraduate Admissions)