Receipt Scanner

Complete User Guide to Receipt Scanner

·8 min read

Welcome to Receipt Scanner! This guide is a complete manual to help you master all of the app’s features, from initial receipt capture to advanced multi-currency budgeting, bill splitting, and data backups.

Unlike traditional finance apps, Receipt Scanner operates 100% locally in your browser. Understanding how to make the most of this local-first architecture will ensure your data remains secure, private, and durable.

1. Getting Started & Installation

Because Receipt Scanner stores all data in your browser’s IndexedDB, browsers may clear this data if the site is not visited regularly or if the device runs low on storage.

To prevent this, you should install Receipt Scanner to your home screen as a Progressive Web App (PWA).

How to Install

  • iOS (Safari): Tap the Share button in Safari, then select Add to Home Screen.
  • Android (Chrome): Tap the three-dot menu icon in Chrome, then select Install App or Add to Home screen.
  • Desktop (Chrome/Edge/Safari): Click the install icon in the right side of the address bar.

Why Installation Matters

  1. No Inactivity Eviction: On iOS, Safari automatically clears website storage after 7 days of inactivity. Installing the app on your home screen exempts it from this rule.
  2. Offline Availability: Once installed, the application is cached on your device, allowing you to scan receipts and review expenses offline without an internet connection.
  3. Fullscreen Experience: Receipt Scanner runs in its own window, giving you more screen space and removing browser address bars.

2. Scanning Receipts & OCR

Receipt Scanner uses PP-OCRv6 tiny running on ONNX Runtime Web inside WebAssembly. This means receipt scanning is done entirely on your device’s processor—your receipt photos are never uploaded to a server.

The Capture Process

  1. Navigate to the Scan tab.
  2. Tap Take a photo to launch your device’s camera, or Choose a file to upload an image from your photo gallery.
  3. Once captured, the app runs canvas-level image preprocessing (percentile contrast stretching and greyscale) to optimize readability.
  4. The WebAssembly OCR engine processes the image in a few seconds (leveraging multithreading on supported browsers).

Tips for Perfect Scans

To maximize OCR accuracy and reduce extraction errors:

  • Fill the Frame: Get as close to the receipt as possible. Aim for at least 20 pixels of height per character.
  • Flatten the Paper: Distorted, curled paper baselines confuse the text detector. Flatten the receipt on a flat surface.
  • Avoid Glare and Shadows: Move away from direct spotlights that wash out thermal paper print. Bracing your elbows helps prevent motion blur.
  • Long Receipts: If a receipt is extremely long, scan it in two overlapping halves rather than backing far away.

3. The Review & Confirmation Form

No OCR engine is 100% accurate, which is why the Review & Confirmation screen is a core design element of Receipt Scanner. Nothing is written to the database without your explicit approval.

Important: You must verify every field against the original receipt. Receipt Scanner is not liable for incorrect scans, missing or wrong amounts, or any payment, tax, legal, or compliance issue that results from using the app. It is a free assistance tool only—not accounting, tax, or payment software. See the Terms of Service.

Reviewing Extracted Fields

The review form displays the receipt photo alongside the extracted fields:

  • Merchant: Competes with logo noise and headers, so it may need manual correction.
  • Date & Time: Extracted based on standard patterns. If the date order is ambiguous (e.g. 03/04/2026), the app utilizes your locale preference or falls back to today’s date if unreadable.
  • Totals (Total, Subtotal, Tax, Tip): Receipt Scanner runs an arithmetic cross-check. If Subtotal + Tax + Tip = Total, it boosts confidence in those fields.
  • Category: Selected automatically based on merchant name keywords, but you can change it via the Category chips.
  • Payment Method: Pre-filled based on receipt text (e.g. “Cash”, “Visa”, “UPI”) or left blank for you to choose.
  • Invoice Number & Tax ID: Extracted when found so you can keep them with the record. Always verify against the original if you need them for claims or filings.

Confidence Badges

Fields parsed with low confidence are highlighted with a “check this” flag. Focus your review on these flagged fields first.

Managing Storage Space

At the bottom of the review form, you can toggle Keep receipt photo.

  • Enabled: Saves the receipt photo in your local browser database. Recommended for tax and audit compliance.
  • Disabled: Discards the image binary and only saves the text ledger data. Highly recommended if you want to save storage space and prevent database bloat.

4. Organizing with Expense Books

In Receipt Scanner, Books represent the top-level purposes you track money for (e.g., “Personal”, “Work Expenses”, “Europe Trip 2026”). Books are separate from Categories:

  • Books answer: What project/context is this spend for?
  • Categories answer: What physical type of product/service was it?

This orthogonal design means you can have a “Dining” category expense in your “Personal” book and another “Dining” category expense in your “Work Expenses” book without them colliding.

Creating and Customizing Books

  1. Click the Book Switcher dropdown in the top navigation.
  2. Select New Book.
  3. Choose an emoji icon, a background accent color, a book type, and a default currency.
  4. When scanning a new receipt, it will automatically default to the active book. You can change this book target inside the review form prior to saving.

Book Types

  • General (Simple): Standard expense listing.
  • Trip or Project: Displays a running grand total and date span, ideal for bounded travel or project budgets.
  • Recurring Budget: Focuses on monthly cycles and limits.

5. Budgets & Spending Limits

Track your spending constraints directly on your device. Receipt Scanner lets you assign budgets to individual Books and customize category caps.

Setting up a Budget

  1. Open the book switcher, click the settings cog next to your book, or navigate to the Budgets tab.
  2. Toggle Enable primary budget.
  3. Enter your budget limit amount, choose the currency, and set the period:
    • Per day, week, month, or year: Recurring limits.
    • Total (one pot): A fixed limit for the book, optionally bounded by a start and end date (perfect for trips).
  4. Optionally, define Category Caps under the budget settings to restrict categories (e.g., limiting “Food & dining” to $200 of your monthly budget).

6. Splitting Bills & Balances

If you share expenses with roommates, partners, or travel companions, you can enable the Split Bill feature on any book.

Managing a Split Book

  1. Open Book Settings and toggle Split Bill.
  2. Add the names of the participants.
  3. Mark one participant as Self (representing your own spending).

Recording Split Expenses

When saving or manually creating an expense, a Split details section appears:

  • Paid By: Select who initially paid the bill.
  • Split Method:
    • Equally: Divides the cost evenly among all selected participants.
    • Exact amounts: Manually input the specific currency amount for each person.
    • Percentages: Split by percentage share.
    • Shares: Split by ratios (e.g. 2 shares to 1 share).

Settling Debts

  1. Navigate to the Insights tab and select the split book.
  2. Scroll to the Settle Balances panel.
  3. The dashboard shows who owes what, along with Suggested Transfers to clear all debts in the fewest possible payments.
  4. Since Receipt Scanner has no backend server or multiplayer sync, you can copy the settlement breakdown text or download it to share with your group via chat (e.g. WhatsApp, iMessage).
  5. When a repayment is made, click Record Settlement to enter the transfer and update everyone’s balances.

7. Data Safety, Backups & Restores

Since all data lives in your browser’s local sandbox, you must take active responsibility for backing up your records.

Requesting Durable Storage

On your first visit, Receipt Scanner requests durable storage from your browser. This tells the browser’s operating system not to delete your database even if disk space runs low. Check the status indicator under My expenses settings to confirm if your browser has granted this permission.

Regular Backups

Navigate to My expenses and open the backup panel:

  • Export JSON (Device Backup): This creates a complete file containing all books, expenses, budgets, split rosters, and settlements. Always back this up regularly. It is the only way to restore your full ledger on another browser, device, or after a browser reset. (Note: Photo binaries are excluded to keep file sizes manageable).
  • Export CSV (Spreadsheet): Generates a CSV file of your expense list, formatted for Excel, Google Sheets, or Numbers. Note that CSVs cannot be used to restore your database.

Restoring Data

To restore your data on a new device or browser, navigate to the backup settings, click Restore Backup, and upload your exported JSON backup file. This will merge or overwrite your current database.

8. Troubleshooting FAQ

  • The scanner won’t start: Ensure you have granted camera permissions. If you are on an older browser, confirm that WebAssembly is supported and that third-party scripts are not blocking the local WASM runtime compilation.
  • My data disappeared: Did you recently clear cookies/site data, browse in Private/Incognito mode, or use Safari on a site you hadn’t visited in a week? Without a home-screen install or a JSON backup, data cleared by the browser cannot be recovered.
  • Currency matching is wrong: Receipt Scanner matches currency symbols. If it misreads a symbol, it uses the active book’s default currency. You can adjust the default currency in your Book Settings or device preferences.
  • OCR is running slowly: Multithreading requires specific security headers (COOP and COEP) that allow SharedArrayBuffer memory access. In some environments (like standard local preview servers), the app may fall back to single-threaded mode, which takes longer.

Put it into practice

Scan receipt