Mint shut down in March 2024, and a lot of people discovered something they had not thought about while it was running: to use it, they had been handing a company continuous read access to every transaction in their bank account.

Most of the replacements work the same way. Open one and the first screen asks you to log into your bank through an aggregator. If you would rather not, the usual outcome is that you close the app and go back to nothing.

This article is about the other category: expense trackers where you type the numbers in yourself. They are less convenient, they are more private, and there is a reasonable argument that they work better.

What bank linking actually involves

When an app offers to connect your bank, it is almost never the app talking to the bank. It is an aggregator, and that aggregator holds a connection that can read your transaction history on an ongoing basis.

That arrangement is normal, widely used, and mostly fine. It also means your complete spending history sits with a company you did not choose, whose name you may not know, and whose future you cannot predict. Mint's shutdown was a reminder that these arrangements are not permanent.

There is a second, quieter problem. An aggregator cannot see cash. If you pay for anything in notes, an automatic tracker has a hole in it and no way of telling you.

Why manual tracking works better than it should

The obvious objection to typing it in yourself is effort. The less obvious counterpoint is that the effort is where most of the value is.

An automatic tracker shows you a report of what already happened. You read it afterwards, feel briefly informed, and change nothing, because by the time you see the number the decision is weeks old.

Manual entry puts the attention at the moment of the decision instead. You are conscious of the amount as you commit to it rather than a month later in a pie chart. People who have used both routinely report the same thing: they became more careful under manual tracking and no more careful under automatic tracking, despite automatic tracking having strictly better data.

Which is the real trade. Automatic tracking optimizes for completeness of the record. Manual tracking optimizes for awareness at the point of spending. Only one of those actually changes what you do.

The version that records what you did not spend

There is a variant worth knowing about, because it is the one thing no bank feed can ever do, even in principle.

Every transaction-based tool, automatic or manual, can only record money leaving. The times you decided against something produce no transaction at all: no line in the feed, nothing to import, nothing to categorize. They are invisible to the entire category.

But those decisions have amounts attached and they are the reason there is money left at the end of the month. So you can run a tracker that records the opposite: what you were ready to spend, what you actually spent, and the difference kept as a running total.

This is only possible manually. There is no data source in the world that knows you nearly bought something. That makes it one of the few places where typing it in yourself is not a compromise but the only way the thing can exist.

What to look for in a private expense tracker

No bank integration at all, rather than an optional one. A feature that is off by default is a setting you have to trust. An app with no integration in it cannot read your account whatever anybody does.
No account. If there is no sign-up there is no password, no server holding your identity, and nothing to be exposed in someone else's breach.
Local storage you can see. Data on the device, included in your own phone backup, rather than in a database belonging to the developer.
Export. If you cannot get your data out as a CSV, you do not really have it. This is also your insurance against the app disappearing the way Mint did.
An honest privacy page. Look for one that describes what the app does do rather than only what it does not. "We collect nothing" is easy to write and easy to outgrow; a page that names each request the app can make has clearly been checked recently.
No analytics SDK. Plenty of otherwise-private apps still ship a third-party analytics library, which is a network call to somebody else on every screen you open.

The honest downsides

Manual tracking has real costs and you should know them before switching.

You will miss things. Nobody logs every purchase for long, and if your goal is a complete audited record of your spending, a bank feed will beat you every time. You also lose automatic categorization, balance tracking and net worth, which for some people are the entire point.

And local-only storage means device loss is data loss unless your phone backup is working. That is a genuine trade for not having your history on somebody's server, but it is a trade rather than a free win.

If you want the complete picture of every dollar, connect the bank. If you want to change how you spend, and you would rather not hand your transaction history to a third party, manual is the better tool for the job.

What we built

Keep the Diff is the second kind: a manual tracker for the money you decided not to spend. It has no bank integration, no account, no analytics and no ads. Everything you log stays on the device, and Premium exports the lot as a CSV.

The one time it uses the network is unlocking Premium on a Mac or a PC, and only if you ask it to; that request carries a short code and a receipt number and nothing you have written down. We say this specifically rather than claiming there is no networking at all, because we made exactly that claim once and it went out of date. The longer version is here, and the privacy policy is one page.

Expense trackers that don't link your bank, and why manual wins