Transactions

Transactions are the core of Expense Tracker. Every income or expense you record becomes a transaction that feeds into budgets, goals, analytics, recurring detection, and forecasting.

Adding a Transaction

Click the + Add Transaction button in the header (or press N). A form modal will appear with the following fields:

Field	Description	Required
Type	Choose Income or Expense	Yes
Amount	The transaction amount (must be greater than 0)	Yes
Category	Select from default categories or type a custom one	Yes
Date	When the transaction occurred (defaults to today)	Yes
Note	Optional description or memo	No

Receipt Attachments

After adding a transaction, you can attach a receipt image to it. Receipts are stored locally in your browser's IndexedDB database — they never leave your device.

Attaching a Receipt

1. Click the receipt/attachment icon on any transaction in the list
2. Select an image file from your device
3. The image is stored and linked to the transaction

Viewing a Receipt

Transactions with receipts show a receipt indicator. Click it to open the receipt viewer, which displays the full-size image along with metadata (filename, file size, date attached). You can also delete the receipt from the viewer.

Search & Filter

The transactions section includes powerful filtering tools:

• Search — Type in the search bar (or press /) to search by note, category, or amount
• Category Filter — Dropdown to show transactions from a specific category only
• Type Filter — Filter by income, expense, or show all

Filters combine together. For example, you can search for "coffee" within the "Dining" category for expenses only.

Editing & Deleting

Each transaction in the list has action buttons:

• Edit — Opens the transaction form pre-filled with the current values. Modify and save.
• Delete — Shows a confirmation dialog. Once confirmed, the transaction and any attached receipt are permanently removed.

Pagination

Transactions are displayed in pages of 10 items by default. Use the pagination controls at the bottom of the transaction list to navigate between pages. The current page and total count are always visible.

Budgets & Goals

Expense Tracker offers two complementary systems for controlling your spending: Budgets for category-based spending limits and Goals for broader spending targets with progressive alerts.

Budgets

Budgets let you set a spending limit for a specific category over a specific period. The app tracks your actual spending against the budget in real-time.

Creating a Budget

From the Budget Overview section on the dashboard, click Manage, then Add Budget. Configure:

Field	Description
Category	The expense category to track (e.g., Groceries, Dining)
Amount	Maximum spending limit for the period
Period	Monthly, Quarterly, or Yearly

Budget Progress

Each budget displays a color-coded progress bar:

Spent	Color	Status
< 80%	Green	On track
80% – 90%	Yellow	Getting close
90% – 100%	Orange	Almost exceeded
> 100%	Red	Over budget

Budget Alerts

The app automatically sends notifications to the Notification Center when:

• 90% reached — Warning that you're close to your budget limit
• 100% reached — Alert that you've exceeded your budget

Spending Goals

Goals are similar to budgets but designed as broader spending limits with more granular notifications. They can apply to a specific category or all categories combined.

Creating a Goal

Open Settings → Goals tab, then click Add Goal. Configure:

Field	Description
Name	A descriptive name (e.g., "Monthly dining limit")
Amount	Spending limit amount
Period	Monthly, Quarterly, or Yearly
Category	Specific category or "All Categories"

Goal Notifications

Goals trigger progressive notifications:

• 80% reached — Early warning
• 90% reached — Critical warning
• 100% reached — Goal exceeded alert

Notification flags automatically reset when your spending decreases below a threshold (e.g., at the start of a new period).

Managing Goals

From Settings → Goals, you can:

• Enable/Disable a goal without deleting it (toggle switch)
• Edit the goal's name, amount, period, or category
• Delete a goal permanently

Analytics & Forecast

Expense Tracker provides powerful visual analytics and a machine-learning-inspired cash flow forecasting engine to help you understand and predict your finances.

Spending Analytics

The Analytics section on the dashboard has two tabs:

Category Analysis

Displays a donut chart showing the breakdown of your expenses by category. The center shows the total amount. Below the chart, a detailed breakdown table lists each category with its amount and percentage. This gives you instant visibility into where your money is going.

Trends

Displays line charts showing your income and expense trends over time. The chart auto-scales to fit your data and shows labeled axes. Use this to spot spending patterns and seasonal variations.

Automated Insights

The analytics engine automatically generates insights about your finances:

Insight	Description
Top Spending Category	Your highest expense category with its percentage of total spending
Savings Rate	Analysis of what percentage of income you're saving, with recommendations
Daily Average	Your average daily spending amount
Transaction Frequency	Average number of transactions and their typical amount
Expense Ratio	Spending as a percentage of income
Largest Expense	Your single biggest expense transaction

Recurring Pattern Detection

The app automatically analyzes your transaction history to detect recurring expenses like subscriptions, rent, and regular bills.

How It Works

1. Grouping — Transactions are grouped by category and similar amounts (within 20% tolerance)
2. Interval Analysis — The app calculates the average number of days between each occurrence
3. Consistency Check — Verifies that intervals are consistent (within 20% of the average)
4. Classification — Assigns a frequency label based on the interval

Detected Frequencies

Frequency	Interval Range
Weekly	6 – 8 days
Bi-weekly	13 – 15 days
Monthly	28 – 32 days
Quarterly	88 – 95 days
Yearly	360 – 370 days

A minimum of 3 occurrences is required to detect a pattern. Each detected pattern shows a confidence score (0–100%) based on how consistent the intervals and amounts are.

Cash Flow Forecast

The forecast engine projects your finances 90 days into the future using a hybrid algorithm.

Algorithm

The forecast combines two techniques for more accurate predictions:

• Linear Regression (70% weight) — Fits a trend line to your historical data to project the direction of your finances
• Moving Average (30% weight) — Smooths out short-term fluctuations to capture your typical spending level

Additionally, upcoming recurring expenses (detected by the pattern engine) are factored into the projection.

Forecast Insights

The forecast section provides several key insights:

• Trend Direction — Whether your finances are trending positive, negative, or stable
• Projected Growth/Decline — Estimated change amount over the forecast period
• Negative Balance Warning — If projected, shows how many days until your balance goes negative
• End Balance — Projected balance at the end of the 90-day period
• Upcoming Recurring — Count and total of detected recurring expenses due

Forecast Chart

A continuous line chart shows your historical balance alongside the projected forecast. The transition point between real and predicted data is clearly visible, letting you see how the prediction extends from your actual spending patterns.

Settings & Data Management

Open Settings by clicking the gear icon in the header or pressing S. The Settings panel contains five tabs for managing your app configuration, goals, currency, PWA features, and app information.

Data Tab

The Data tab provides tools for managing your financial data:

Export Data (JSON)

Exports all your data as a JSON file, including transactions, budgets, goals, settings, notifications, and receipt images. This is the most complete backup format — use it to transfer your data between devices or create regular backups.

Export CSV

Exports your transactions as a CSV file for use in spreadsheets (Excel, Google Sheets). The CSV also includes summary sections for budgets and goals. Receipt indicators are included but not the actual images.

Import Data

Restore from a previously exported JSON file. This will import all entities: transactions, budgets, goals, settings, notifications, and receipts. Imported data is merged with existing data.

Dummy Data

The "Add Dummy Data" button generates 50+ sample transactions with realistic recurring patterns (rent, salary, groceries, subscriptions), along with sample budgets. Useful for testing and exploring the app's features.

Goals Tab

Manage your spending goals directly from the Settings panel. See the Budgets & Goals section for detailed information on creating and managing goals.

Currency Tab

Choose your preferred currency from the 9 supported options. When you change currency, all amounts in the app are converted automatically using exchange rates.

Custom Exchange Rates

If the default exchange rates don't match current market rates, you can override them:

1. Select your target currency
2. Click Custom Exchange Rates
3. Enter your preferred rates for each currency pair
4. Click Save

Use the Reset to Defaults button to restore the built-in exchange rates.

PWA Tab

The PWA (Progressive Web App) tab shows your installation status and provides tools for managing the app's offline capabilities.

Installation

Click Install App to add Expense Tracker to your device's home screen or desktop. Browser-specific instructions are provided:

Browser	Installation Method
Chrome	Click the install icon in the address bar, or use the Install button
Edge	Click the install icon in the address bar, or go to Apps menu
Firefox	Add to Home Screen from the browser menu
Safari (iOS)	Tap Share → "Add to Home Screen"

Cache Management

The Clear Cache button removes cached files from the service worker. This is useful after app updates to ensure you're running the latest version. After clearing the cache, reload the page to re-cache fresh files.

PWA Features

• Works offline — track expenses without internet
• Install on any device — Windows, Mac, iOS, Android
• Fast loading — cached resources load instantly
• App-like experience — no browser UI, feels native
• Home screen shortcut — quick access like any app

Info Tab

The Info tab displays your app statistics at a glance:

Item	Description
App Version	Current version of Expense Tracker Pro
Storage Used	Amount of browser storage consumed (in KB)
Transactions	Total number of recorded transactions
Budgets	Number of configured budgets
Goals	Total number of spending goals
Recurring Patterns	Number of auto-detected recurring expenses
Total Categories	Number of unique categories used
Income/Expense Breakdown	Count of income and expense transactions

How Data is Stored

Expense Tracker uses two browser storage mechanisms:

LocalStorage

Stores structured data as JSON strings:

• expenseTracker_transactions — All transaction records
• expenseTracker_budgets — Budget definitions
• expenseTracker_goals — Spending goals
• expenseTracker_settings — App configuration (currency, theme, etc.)
• expenseTracker_notifications — Notification history

IndexedDB

Used exclusively for receipt image storage. The database ExpenseTrackerReceipts stores images as base64 data linked to transaction IDs. IndexedDB handles much larger data sizes than LocalStorage, making it suitable for image storage.