About Flow

What is Flow?

Flow is a free, privacy-focused tool that transforms your bank transaction data into beautiful, interactive Sankey diagrams. Unlike traditional budgeting apps that require you to connect your bank accounts or upload sensitive data to their servers, Flow processes everything locally in your browser.

Simply export your transactions from your bank as a CSV or Excel file, drop it into Flow, and instantly see where your money goes. No sign-ups, no subscriptions, no data collection.

Why Sankey Diagrams?

Sankey diagrams are a type of flow visualization that shows how values move from one set of categories to another. The width of each flow represents its proportional value, making it immediately obvious where the bulk of your money is going.

This visual approach makes it easy to spot patterns that might be hidden in spreadsheets or pie charts. You can see at a glance that your "Food" category is dominated by restaurant spending, or that your "Shopping" expenses are mostly going to a single retailer.

Key Features

• 1

  Privacy-First Design

  All processing happens in your browser. Your financial data never leaves your device and is automatically cleared when you close the page.

• 2

  Smart Categorization

  Flow automatically categorizes your transactions based on merchant names, grouping expenses into categories like Food, Shopping, Transportation, and more.

• 3

  Subscription Detection

  Identifies recurring charges to help you track your monthly subscriptions and spot services you might have forgotten about.

• 4

  Top Merchant Analysis

  See which merchants receive the most of your money, helping you identify spending habits and potential areas to cut back.

• 5

  Multiple File Support

  Upload statements from multiple accounts or time periods and see them combined into a single comprehensive view.

How to Use Flow

1. Export your transactions - Download your bank statement as a CSV or Excel file from your online banking portal
2. Upload to Flow - Drag and drop your file onto the upload area, or click to browse
3. Explore your spending - View the Sankey diagram, click categories to drill down, and review your subscriptions
4. Take action - Use the insights to make informed decisions about your budget

Supported File Formats

Flow supports the most common bank export formats:

• CSV files (.csv) - Comma-separated values, the most universal format
• Excel files (.xlsx, .xls) - Microsoft Excel spreadsheet format

Your file should contain columns for Date, Description, and Amount (or separate Debit and Credit columns). Most bank exports follow this format automatically.

Open Source

Flow is built with modern web technologies including Next.js, React, and D3.js. We believe in transparency, which is why our code is open for inspection. This ensures you can verify that your data truly stays private.