CBSE On Screen Marking (OSM) Portal — Login and Complete Guide

The Central Board of Secondary Education (CBSE) has introduced On Screen Marking (OSM) for evaluating Class 12 board examination answer sheets digitally. This guide explains what OSM is, how evaluators can log in to the CBSE OSM portal, system requirements, and how to resolve common issues.

Disclaimer: CitizenNest is an independent informational platform and is not affiliated with CBSE or any government body. Always refer to official CBSE communications for the latest updates.

What Is CBSE On Screen Marking (OSM)?

On Screen Marking (OSM) is a digital evaluation system where examiners check scanned copies of students' answer sheets on a computer screen instead of physically handling paper answer books. CBSE introduced OSM for Class 12 board exams starting from 2026 to:

• Reduce errors in totalling and mark entry
• Speed up the evaluation and result declaration process
• Increase transparency through digital audit trails
• Enable quality monitoring of evaluation in real time

Under OSM, physical answer books are scanned at designated centres, quality-checked, and then made available on the online evaluation portal. Evaluators log in and mark each answer on screen using predefined marking schemes.

Who Uses the CBSE OSM Portal?

The OSM portal is used by:

• Evaluators/Examiners — Teachers appointed by CBSE to evaluate Class 12 answer sheets
• Head Examiners — Senior evaluators who supervise and review marking
• School Principals — Who monitor their teachers' OSM participation via the dashboard
• CBSE Officials — For quality control and real-time monitoring

Teachers of Classes XI and XII at CBSE-affiliated schools are required to complete a mock evaluation (practice session) on the OSM portal before the main evaluation begins.

CBSE OSM Portal URLs

How to Login to CBSE OSM Portal — Step by Step

Follow these steps to log in and start evaluating answer sheets:

Step 1: Get Your Login Credentials

• CBSE sends login credentials (User ID and Password) to evaluators via their registered email address linked to the OASIS portal.
• Ensure your email ID is updated in the CBSE OASIS system. If you have not received credentials, contact your school principal or the CBSE regional office.

Step 2: Open the OSM Portal

1. Open a web browser (Google Chrome recommended) on your computer.
2. Go to cbse.onmark.co.in/cbseevalweb/.

Step 3: Enter Login Details

1. Enter your User ID (typically your CBSE examiner code or registered email).
2. Enter your Password as received via email.
3. Click Login.

Step 4: Complete the Mock Evaluation (First-Time Users)

• If this is your first time, you will be directed to a practice/mock evaluation session.
• Complete the mock evaluation to familiarise yourself with the marking tools and interface.
• This step is mandatory before you can access actual answer sheets.

Step 5: Start Evaluating

1. After login, select the assigned subject from your dashboard.
2. The scanned answer sheet appears on one side of the screen.
3. A digital marking panel appears on the other side.
4. Award marks question-wise using the predefined step markings aligned with the official marking scheme.
5. Mark unattempted questions as 'NA' (Not Attempted).
6. The system will not allow submission until every question has been marked.
7. Submit the evaluated answer sheet.

Step 6: Review and Submit

• Review your marks before final submission.
• Once submitted, marks are recorded in the system and cannot be easily changed.

System Requirements for CBSE OSM Portal

To use the OSM portal smoothly, ensure the following:

Important Rules for Evaluators

1. IP-Based Access Control — You can only log in from authorised locations (typically your school). If the IP address does not match, the system will block access.
2. Complete All Questions — The system requires marks for every single question. Unattempted questions must be marked as 'NA'.
3. Follow the Marking Scheme — Use only the predefined step markings provided by CBSE.
4. Do Not Share Credentials — Your login ID and password are confidential. Do not share them with anyone.
5. Complete Mock Session First — The practice evaluation must be completed before actual marking begins.

Common Issues and Solutions

Login Credentials Not Received

• Check your spam/junk folder for emails from CBSE or OnMark.
• Verify that your email is correctly updated in the CBSE OASIS portal.
• Contact your school principal who can check the OSM monitoring dashboard.
• Reach out to the CBSE regional office if the issue persists.

Unable to Login — IP Address Error

• You must log in from the authorised school network. Home or personal networks may not be permitted.
• Ask your school IT administrator to confirm the registered IP address with CBSE.

Portal Not Loading or Slow

• Use Google Chrome browser. Other browsers may have compatibility issues.
• Clear browser cache and cookies.
• Ensure stable internet connectivity (minimum 2 Mbps).
• Disable browser extensions that may interfere with the portal.

Scanned Answer Sheet Not Visible or Blurry

• Report the issue through the portal's built-in reporting tool.
• Contact the CBSE evaluation helpdesk for re-scanning if needed.

Forgot Password

• Use the Forgot Password option on the login page.
• A password reset link will be sent to your registered email.
• If you still cannot reset, contact the CBSE helpdesk.

Important Tips

1. Complete the mock evaluation early — Do not wait until the last date. Early completion ensures you are ready when actual answer sheets are assigned.
2. Use a large screen — A bigger display makes it easier to read scanned answer sheets and reduces eye strain.
3. Keep your internet stable — Use a wired connection if possible. Disconnections can cause loss of unsaved marking progress.
4. Update your OASIS profile — Ensure your mobile number and email are current so you receive all OSM-related communications.
5. Take breaks — Evaluating on screen for long hours can cause fatigue. Take regular breaks to maintain marking quality.

CBSE OSM Timeline

Exact dates vary each year. Check cbse.gov.in for current year dates.

Frequently Asked Questions (FAQs)

Q1: What is the CBSE OSM portal URL?

The main evaluation portal is at cbse.onmark.co.in/cbseevalweb/. The monitoring dashboard for principals is at cbseosm.onmark.co.in/CBSE_Dashboard/.

Q2: Who can log in to the CBSE OSM portal?

Only CBSE-appointed evaluators, head examiners, and authorised school principals can log in. Credentials are sent by CBSE to registered email addresses.

Q3: Can I log in to the OSM portal from home?

In most cases, no. CBSE uses IP-based access control, meaning you can only log in from authorised locations, typically your school. Check with your school administration for specific rules.

Q4: What should I do if I did not receive my OSM login credentials?

First check your spam folder. Then verify your email in the CBSE OASIS portal. If the issue persists, contact your school principal or the CBSE regional office.

Q5: Is the mock evaluation mandatory?

Yes. CBSE has made it mandatory for all teachers teaching Classes XI and XII to complete the mock evaluation before the main OSM evaluation begins.

Q6: What happens if my internet disconnects during evaluation?

The system periodically saves your progress. However, any unsaved marks for the current answer sheet may be lost. It is strongly recommended to use a stable wired internet connection.

Q7: Can I change marks after submitting an answer sheet?

Once an answer sheet is submitted, marks cannot be easily changed. Review carefully before clicking the submit button. For corrections, you may need to contact the head examiner.

Q8: Which browser works best for the OSM portal?

Google Chrome (latest version) is recommended. Other browsers like Firefox or Edge may work but are not officially supported.

Q9: Will OSM apply to Class 10 exams as well?

As of 2026, CBSE has introduced OSM for Class 12 exams. Class 10 may follow in subsequent years based on the success of the Class 12 implementation.

Q10: How are answer sheets scanned?

Physical answer books are scanned at designated CBSE centres. Every page, including blank pages, is scanned. A quality check team verifies that all pages are correctly scanned, in sequence, and clearly visible before making them available on the portal.

Last updated: March 2026. For the latest information, visit cbse.gov.in. You may also find our CBSE guide resources helpful for other CBSE-related services.