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Make your own budget planner with AI

Try it first. It's loaded with example numbers so you can see how it works; clear it and add your own. Nothing leaves your device. Then build one that fits exactly how you spend.

Starter 45 to 75 minutes Free · nothing to install No bank linking, nothing uploaded
You're looking at example numbers.
Spent0
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      Click a category's amounts to change its budget. Everything saves in this browser only.

      Watch it come together, start to finish
      What you'll build

      A private budget tracker, built your way

      You'll describe it to a free AI assistant, paste what it writes into a file, and open it in your browser. No spreadsheet skills needed, and no app asking for your bank login.

      • A monthly budget planner: set your income and a budget for each category (rent, food, transport, fun)
      • Log spending in seconds: amount, category, date and a short note
      • See what's left in each category, with bars that turn amber and red as you get close to the limit
      • A pie chart of where your money went this month
      • Savings goals with progress bars
      • Export to a spreadsheet file, and a backup button
      • No bank linking, no account, nothing uploaded. Your data stays in your browser.

      Good for: anyone who has tried budgeting apps and given up, students managing money for the first time, families who want a simple picture of the month, and anyone who'd rather not hand their bank details to an app.

      Before you start

      What you need

      An AI chat assistantClaude, ChatGPT or Gemini. The free version works.
      A plain text editorNotepad (Windows) or TextEdit (Mac; choose Format then Make Plain Text first).
      A web browser
      Optionala rough idea of your monthly income and main costs.
      First time saving an HTML file? Read How to save and open an HTML file. It takes two minutes.
      Never paste real bank details, card numbers or passwords into an AI chat. You don't need to for this project. The AI builds the empty tracker, and you type your numbers into it on your own computer afterwards.
      Step by step

      Build it in six steps

      1. Ask for the tracker

        Copy this prompt into your AI assistant. Change the currency and categories to suit you:

        Copy this prompt
        I don't know how to code. Please make me a personal monthly budget tracker that runs in a web browser.
        
        Requirements:
        - ONE single HTML file (HTML, CSS and JavaScript together), no external libraries, works offline. I will save it and double-click it.
        - Currency: [£ / $ / €].
        - At the top: this month's income (editable), total spent, and what's left.
        - Categories, each with a monthly budget I can edit: Rent/Mortgage, Bills, Food, Transport, Eating out, Fun, Other.
        - A quick "Add spending" form: amount, category (dropdown), date (defaults to today) and an optional note.
        - A list of this month's spending, newest first, with a delete button on each.
        - For each category, show spent vs budget with a progress bar.
        - Save everything in the browser with localStorage, so it's still there when I reopen the file.
        - Clean, friendly design that works on a phone too.
        
        Please give me the complete file in one code block, then tell me in simple steps how to save and open it.

        Copy the code, paste it into your text editor, and save it as budget.html. Double-click the file. Add a test purchase, close the browser, reopen the file, and check it's still there.

      2. Add warning colours and a chart

        Copy this prompt
        That works, thank you. Please add:
        - Category progress bars that are green under 75% of budget, amber from 75% to 100%, and red when over budget, with "£12 over" shown in red
        - A pie chart (drawn with the HTML canvas, no libraries) showing spending by category this month, with a legend and percentages
        - A one-line summary at the top, e.g. "You've spent 62% of your budget and we're 55% through the month"
        
        Send me the complete updated file.
        Always ask for the complete file. Replace everything in budget.html, save, and refresh (F5 or Cmd+R).
      3. Manage categories and months

        Copy this prompt
        Please add:
        - Buttons to add, rename and delete categories (ask "Are you sure?" before deleting, and move that category's spending to "Other")
        - Arrows by the month name so I can look back at previous months. Each month keeps its own spending, but category budgets carry over unless I change them.
        - A "Copy last month's budgets" button
        
        Send me the complete updated file.
      4. Track savings goals

        Copy this prompt
        Please add a "Savings goals" section. I can create a goal with a name, target amount and optional target date (e.g. "Holiday, £1,200 by July"). I can add money to a goal at any time. Show a progress bar for each goal and, if it has a date, how much I'd need to save per month to hit it.
        
        Send me the complete updated file.
      5. Export and back up

        Your data lives in your browser, so a backup matters. A spreadsheet export is handy too.

        Copy this prompt
        Please add:
        - "Export to spreadsheet": downloads this month's spending as a CSV file that opens in Excel, Google Sheets or Numbers
        - "Export backup" and "Import backup": download all my data as a JSON file with today's date in the name, and restore it after confirming
        
        Send me the complete updated file.

        Make a backup at the end of each month and keep it somewhere safe.

      6. Make it yours

        Copy this prompt
        Please restyle the budget tracker as [choose one: a calm, minimal design in navy and white / a friendly, colourful design with an emoji for each category / a dark mode design that's easy on the eyes at night].
        
        Also add a small "Add spending" button that stays in the bottom corner of the screen on phones, so logging a purchase takes one tap.
        
        Send me the complete updated file.
        Tip: the quickest budget is the one you actually update. Bookmark budget.html and log spending once a day, or every time you open your banking app.
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      If it goes wrong

      Quick fixes

      My data disappeared

      Browsers treat a file in a different folder as a different site. If you moved or renamed budget.html, put it back. Keep it in one place and use the backup button regularly.

      The totals don't add up

      Tell the AI exactly what you see:

      Copy this prompt
      I added £10.50 and £4.25 to Food, but the total shows £10.504.25. Please fix how amounts are added up and send me the complete file.

      (That particular bug happens when numbers are joined like text. It's a common one, and the AI will know what you mean.)

      The chart is blank

      Make sure you've added spending for the month you're viewing. If it's still blank, press F12 (Cmd+Option+I on a Mac), open the Console tab and paste any red error text into the chat.

      It opens as text

      Re-save as plain text with exactly .html at the end.

      Make it your own

      Twist it into something else

      Change the first prompt to build:

      A holiday savings tracker

      one big goal with a countdown to your departure date

      A flat-bills splitter

      log shared costs and see who owes whom

      A wedding budget planner

      budget by supplier (venue, catering, flowers), with deposits paid and amounts still owed

      A small-business takings log

      daily sales by payment type, with weekly totals

      A kids' pocket money tracker

      saving, spending and giving jars

      Outgrown the browser? Our upcoming Desktop expense app with charts guide builds a full program with yearly reports.

      Why build it yourself?

      Your finances stay yours

      Your finances are about as private as data gets. With your own tracker, nobody sees your spending, there's no subscription, and no app is quietly analysing your purchases. You choose the categories and decide what counts as "fun".

      This guide is about building a tool, not financial advice.
      Keep going

      What to build next