UPSC CSE Prelims 2025 Answer Key: Download GS 1 & CSAT Answer Key PDF With Solutions!

UPSC CSE Prelims 2025 Answer Key (unofficial) has been released by Testbook for both GS Paper 1 and the CSAT! UPSC 2025 Unofficial Answer Key for General Studies Paper 1 and CSAT 2025 Answer Key is now available for download along with detailed solutions! Candidates who appeared for the UPSC Civil Services (Preliminary) Examination 2025 on May 25, 2025 can download the set-wise answer key PDFs for GS Paper 1 & CSAT to evaluate their performance and estimate their Prelims marks. These unofficial keys released by Testbook are crucial for candidates who are awaiting the UPSC Prelims 2025 Official Answer Key PDF, which will be published later on the official website of the UPSC, tentatively in June-July 2026. 

Download UPSC CSE Prelims 2025 Answer Key PDF [GS Paper 1, SET D]

Download UPSC CSAT 2025 Answer Key PDF [SET A]

Check out: UPSC Prelims 2025 Question Paper and UPSC Prelims Paper Analysis 2025.

UPSC CSE Prelims 2025 Answer Key

The official UPSC Prelims 2025 Answer Key will be released by the Union Public Service Commission after the final UPSC Result 2025 is declared, tentatively in June-July 2026. However, aspirants who have written the UPSC Civil Services Preliminary Examination 2025 conducted on May 25, 2025 can check the unofficial Answer Keys released by Testbook to cross-verify their performance. Candidates who appeared for the exam can now access the unofficial UPSC Prelims 2025 answer key PDFs for both General Studies Paper 1 and CSAT Paper 2 curated by Testbook for performance analysis before the UPSC prelims 2025 official answer key PDF is published on the UPSC website. 

Know the Subject Wise Weightage of Prelims GS Paper 1 & Difficulty Level!

UPSC Prelims 2025 Answer Key PDF Download – GS Paper 1

The General Studies Paper 1 consists of 100 multiple-choice questions (MCQs) for 200 marks. There is a negative marking of 0.66 marks per incorrect answer. Candidates can check and download the set-wise GS Paper 1 answer keys below:

Also download year-wise UPSC CSE Prelims Answer Key for last-minute revision using previous question papers – 

• UPSC Prelims 2023 Answer Key

• UPSC Prelims 2022 Answer Key

• UPSC Prelims 2021 Answer Key

UPSC CSAT 2025 Answer Key

The Civil Services Aptitude Test (CSAT) is Paper 2 of the Prelims exam and is qualifying in nature. Candidates must score a minimum of 33% (66 marks) to qualify. The CSAT 2025 Question Paper comprised 80 questions, with a focus on reasoning, comprehension, and numerical ability.

Below are the links to the UPSC CSAT paper 2025 answer key for all sets:

Download the UPSC Prelims 2025 Question Paper: GS Paper 1 & CSAT PDF!

UPSC Prelims 2025 Answer Key: Marking Scheme

Candidates must refer to the marking scheme set by the Union Public Service Commission to estimate their marks using the unofficial UPSC Prelims 2025 Answer Key. Refer to the table below to estimate your scores using the unofficial GS Paper 1 and CSAT 2025 Answer Key released by Testbook -

• CSAT is qualifying and not counted in the calculation of final marks.
• Avoid careless negative marks by using the 2025 prelims answer key strategically.

Estimate your Prelims Marks by using the UPSC Marks Calculator & UPSC Negative Marking Calculator. 

How to Download UPSC Prelims 2025 Official Answer Key PDF?

The UPSC Prelims 2025 answer key for both GS Paper 1 and CSAT Paper 2 will be released once the Mains & Interview/Personality Test rounds are complete. To download the official GS Paper 1 and CSAT 2025 Answer Key from the official website, follow the steps given below -

• Visit the official UPSC website: https://www.upsc.gov.in
• Navigate to the ‘Examinations’ tab
• Click on ‘Answer Keys’
• Locate ‘UPSC Prelims Answer Key 2025’
• Choose the set you attempted and click to download the set wise official UPSC Prelims Answer Key PDF for GS Paper 1 and GS Paper 2.

Only this UPSC CSE  Prelims 2025 Answer Key will be treated as final by UPSC during the evaluation process.

Why Use the Unofficial UPSC Prelims 2025 Answer Key?

The final UPSC Prelims 2025 Answer Key is released by the Union Public Service Commission one year after the Prelims Exam Date, tentatively in June-July 2026, once the Mains and Interview rounds are conducted. Meanwhile, candidates are often perplexed to check their performance by matching their responses with the correct exam answers. For this purpose unofficial UPSC CSE Prelims 2025 Answer Key is extremely resourceful for candidates. Here's why you must refer to the unofficial UPSC 2025 Prelims Answer Key -

• Cross-check responses from the CSAT 2025 Question Paper and GS Paper 1 
• Identify correct/incorrect answers and calculate your total score 
• If you score anywhere above 89 - 92, you are in the safe zone and will most likely qualify for the UPSC Mains. However, the final selection will depend on the actual UPSC Cut Off Marks released by the Union Public Service Commission. 
• Analyze strengths and weaknesses subject-wise. 
• Adjust your preparation strategy for future attempts

For those awaiting the official release, the unofficial UPSC answer key 2025 can provide timely insights and motivation.

Previous Year UPSC Answer Keys for Practice

For aspirants targeting future attempt of UPSC CSE Prelims, it is crucial to go through the previous year UPSC Prelims Answer Keys for both GS Paper 1 and CSAT to evaluate your performance in UPSC Previous Year Papers. Candidates must keep the question paper with answer keys side by side to evaluate their performance in the Prelims and predict their chances of qualifying for the Mains. Download the year-wise official UPSC CSE Prelims Answer Key of GS Paper 1 and CSAT from the table below -

By practicing with old papers and answer keys, you can gain a clear understanding of UPSC’s evolving pattern.

While the UPSC CSE Prelims 2025 unofficial answer key gives a head start in performance analysis, the official answer key will be treated as the authoritative document. Candidates should use both versions wisely to measure their standing and plan for the UPSC Mains 2025 accordingly.

Keep visiting this space to download the official answer key and cutoff details when published by UPSC! Stay tuned by downloading the Testbook App now!