Nexus: Spaced Repetition Tracker

Saved on this device
YOUR LEARNING AT A GLANCE

Overview

See what needs review and track progress across subjects.

LEARNING INTELLIGENCE

Review analytics

Explore rating trends over time, compare Again to Easy, and export a detailed study report.

Upcoming review calendar

See review dates and exams across the months ahead.

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Plan your next study sessionsMonth-by-month reviews and exam dates

Review queue

Overdue and due topics appear first, followed by new topics.

Progress by subject

Share of active topics reviewed at least once.

Coming up · next 7 days

Plan ahead before topics become overdue.

0 scheduled

Your momentum

Recent study activity from your saved review history.

Last 7 days

Consistency & streaks

Long-term review activity, topic mastery, and your current study streak.

Streams & subjects

Organise your courses and subjects here, alongside your topics.

Topics

Add, edit, filter, and review topics from any subject.

Explore curriculum

Browse ready-made study collections and install only the streams, subjects, or topics you want.

CURRICULUM MARKETPLACE

Build your own study workspace

Starter curricula stay here until you choose to add them. Your personal review schedule and history remain yours.

—available topics
ACCOUNT & DATA

Accounts & Backup

Manage sign-in, cloud sync, and portable backup files.

Account & cloud sync

Private sync across your devices

Connecting…
Signed-in account
Checking account…

You can use Nexus offline. Each signed-in account has its own cloud workspace, and pending offline changes stay associated with that account. If you have unassigned offline study data at your first sign-in, Nexus asks how to handle it before syncing. Switching accounts does not automatically merge their workspaces. Keep periodic JSON backups; when merging, matching record IDs use the offline copy.

Backup & restore

Portable files you control.

A full backup includes tracker data, Study Hub records and preferences, and FSRS review memory and settings. Restore lets you choose REPLACE (replace the workspace) or MERGE (keep current data and add non-duplicate records). When signed in and cloud sync is available, Nexus syncs changes automatically; check the status to confirm they are synchronized.

Data storage: Nexus keeps a durable local copy on this device. When you are signed in and cloud sync is available, successful changes sync to the same account on your other devices. Check the sync status before switching devices. JSON backups remain an independent recovery copy.
PREFERENCES & SCHEDULE

Settings

Manage exams, deadlines, and appearance preferences.

Exams & deadlines

Add as many exam dates as you need.

Appearance

Choose the interface theme.

Theme preference is saved with your workspace on this device and syncs to your account when cloud sync is active.

Danger Zone: Review History / Account Reset

Review-history deletion and full workspace reset are high-impact actions. Read the warnings before continuing.

Review schedule

The schedule adjusts to each rating and the topic's previous interval.

1 — Again
A lapse; FSRS updates memory and schedules a short interval.
2 — Hard
Difficult recall; FSRS schedules a shorter interval.
3 — Good
Successful recall; FSRS calculates the next interval.
4 — Very good
Uses Good’s memory update with an interval between Good and Easy.
5 — Easy
Easy recall; mapped to FSRS’s Easy grade.
Maximum interval
FSRS-6 uses memory stability, difficulty, elapsed time, and desired retention. The maximum interval is controlled above (30–120 days).
YOUR STUDY WORKSPACE

Study Hub

Your plan, practice, and progress — connected.

Review topic

Choose a date to override the suggested interval. Leave blank to use the automatic schedule.

How well did you recall it without looking?

Choose a rating to preview the next due date.

Add topic

A topic can belong to any stream and subject.

Add stream / course

Streams can represent school streams, university courses, certifications, or personal collections.

Add subject

Subject names can be in any language.

Add exam or deadline

Use this for any examination, test, assessment, or deadline.

Install Nexus

Choose how you want to install the app on this device.

If no install prompt appears, open your browser menu and choose “Install app” or “Add to Home screen” where available. Your study data remains on this device unless you enable cloud sync.

Support Nexus

A free tool, made with care for students.

Enjoying Nexus? If it has helped you organise your studies and keep up with revisions, you can optionally support its continued development.

Support independent development

Your contribution helps with hosting, maintenance, and future improvements.

Entirely optional. Nexus remains free, and donating does not unlock features or change your access.

Support Nexus

No subscriptions. No locked features. No pressure.

How to use Nexus

A complete guide to planning, reviewing, tracking progress, and protecting your data.

1. Home and your daily overview

The Home screen brings your study workload together. Check your active topics, topics due today, overdue topics, reviews completed today, and progress by subject. Open Topics to choose a due or new topic and begin reviewing. Due and overdue topics are prioritised ahead of new topics where applicable. Check the upcoming-seven-days view and calendar to plan around future reviews, exams, and deadlines. Use your progress and activity indicators to keep track of consistency; they describe recorded activity, not a guarantee of mastery.

2. Streams, subjects, and topics

Organise any curriculum using streams/courses → subjects → topics. A topic can represent a lesson, chapter, concept, or any unit you want to revisit. Add, edit, search, filter, sort, or delete topics using the available controls. Add notes where useful. The optional starter Commerce collection includes Sinhala A/L Business Studies, Accounting, and Economics topics; you can change it or create a completely different curriculum. Deleting a topic may not remove older review-history snapshots associated with it.

3. How reviews and scheduling work

Open a topic's Review action after trying to recall or explain the material without looking at your notes. Choose the rating that best reflects how well you remembered it, review the next-date preview, add an optional note, and press Mark as reviewed. You can set a custom next-review date when you need to override the suggested date. A review is not saved until you confirm it.

FSRS-6 is integrated into the review workflow and is the default scheduler. It calculates future intervals from each topic’s memory stability and difficulty, your review rating, elapsed time, and desired retention. In Setup & data → Review schedule, you can adjust desired retention (70–97%) and the maximum interval (30–120 days), or disable FSRS-6 to return to the legacy multiplier scheduler. The app has five rating buttons mapped to FSRS’s four grades: 1 — Again, 2 — Hard, 3 — Good, 4 — Very good (uses the Good memory update with an interval between Good and Easy), and 5 — Easy. Existing due dates are preserved; the selected scheduler calculates future intervals when you review. FSRS memory state is stored with topic data and included in full JSON backups. A custom next-review date overrides the suggested due date while the FSRS memory update is still recorded. Check the preview before saving.

4. Review History

Review History records completed reviews, including the date, topic/subject information, rating, interval, due date, and any saved note available for that entry. Use search and filters to locate records, and export the history to CSV for spreadsheet analysis. Clearing history is destructive: it removes the log but should not be treated as a way to reset or recalculate topic schedules.

5. Study Hub

Use Study Hub to plan work and analyse progress beyond the basic review queue. Depending on the section, you can use the daily study plan and time budget, topic mastery and weakness estimates, expected syllabus counts, focus-session logging, exam workload estimates, paper/practice records, a mistake journal, goals, analytics, bulk topic actions, CSV topic import, and expanded backup tools. Planning estimates are aids for prioritisation; they do not replace your own judgement or automatically prove that a topic is mastered. The scheduling selector currently offers Classic intervals and the adaptive heuristic described above.

6. Exams, deadlines, and calendar

Add an upcoming exam, assessment, paper, or other deadline with its name and date. Use the countdown and calendar to see what is approaching and plan your workload. Keep dates accurate when an exam is postponed. Past entries may remain as records; edit or delete entries you no longer need.

7. Sign-in, cloud sync, and account separation

If sign-in and cloud sync are available in your build, sign in with the account you intend to use and follow the app's prompts to choose or sync data. Keep each person's work in their own account: signing in to another account must not be treated as a way to share or merge personal study data automatically. Before choosing any option that replaces local or cloud data, read the confirmation carefully and make a backup. When the same account is used on multiple devices, Nexus now attempts to combine independent offline and cloud edits automatically. The three-option data choice is reserved for unassigned offline work at first sign-in or when switching accounts, not routine same-account sync. If reconciliation cannot be completed safely, Nexus preserves pending work and pauses rather than claiming it synced. Keep a JSON backup as an independent copy.

8. Backup, restore, and exports

Use the full JSON backup option to preserve the app data supported by that backup format. Store the file somewhere separate from the browser or device. Use Restore only after checking that you selected the intended backup; restoring can replace the current data. CSV exports are useful for spreadsheets and analysis, but they are not full app backups and generally cannot restore every setting or linked record. CSV topic import is for importing topic data in the format the app supports. Make a fresh backup before major imports, restores, account changes, or device changes.

9. Theme, installation, and offline use

The theme control cycles through the system preference, light, and dark appearances. On a supported browser, use Install or the browser menu's Install app/Add to Home Screen option to install Nexus. Offline use depends on the app having been loaded and cached successfully while online. Some account and cloud features require an internet connection. An installed app does not guarantee that unsynced data is backed up remotely.

10. Data protection and notifications

Local browser data can be lost if site data is cleared, the browser profile is removed, or the device is lost. Cloud sync, where enabled and confirmed successful, is separate from local storage; a JSON backup is a separate portable copy. CSV exports are for selected data, not a substitute for the full backup. Browser notifications require browser support and permission. In-app reminders can be checked while using Nexus, but notifications are not guaranteed to run after the app/browser has closed unless the relevant push-notification infrastructure is available and configured. Avoid relying on one device or one copy for important study records.

11. Reset all data

Reset all data clears tracker and Study Hub records and settings on this device, including review history, papers, journal entries, goals, FSRS memory, and scheduler preferences. When signed in with cloud sync active, the empty workspace can sync to your account and affect other devices. Export a full JSON backup first, then read the confirmation carefully.

A practical daily workflow
Saved.
ACCOUNT SETUP · DATA CHOICE

Choose how to handle your study data

Nexus found study data on this device. Choose how it should be handled before syncing with this account. This choice is needed only when local data is not yet associated with this account.

Merge offline data

Combine this device’s study data with the signed-in account’s cloud data. Matching records use the offline copy, so review the result afterward.

Use cloud data on this device

Replace the study data on this device with the signed-in account’s cloud backup. Any unsynced offline changes on this device will be discarded.

Replace cloud data with offline data

Upload this device’s study data and overwrite the signed-in account’s existing cloud copy. The cloud version may be lost; choose only if this device has the version you want to keep.

Your choice takes effect before syncing begins. If unsure, choose Merge. Downloaded JSON backups remain untouched.
FOCUS SESSION
00:00
Ready when you are

Deep work, one thing at a time.

Session target · —Saved locally · works offline

Keep this window open while you study. Stop the session to return to the rest of Nexus.

PLAN AHEAD

Review calendar

Upcoming reviews and exam dates, at a glance.

Reviews due Exam