Source-available · Free forever · Yours to self-host

Bookkeeping that stays on your computer

SlowBooks Pro is a free, source-available accounting app for Windows, Mac, and Linux. No cloud, no subscription, no account to create. Your books live on your hard drive, where they belong.

Signed Windows installer, verified publisher macOS: Developer ID signed and notarized by Apple Windows · Mac · Linux AA contrast · tagged PDFs Analytics & AI · v2.29.1 No telemetry or account
SlowBooks Pro Server Edition: the complete left menu, from Dashboard to Companies, beside the Copperline Woodworks snapshot: $70,993.52 receivable, $40,891.36 payable, $271,149.29 in checking, the A/R aging bar, twelve months of revenue, recent invoices and payments, this month's and the year's profit, and the balance sheet trend climbing to $431k of assets.
What makes SlowBooks different

Where your books actually live

Every other accounting app today wants you to host your books on their servers. SlowBooks doesn’t. It runs on the computer in front of you, and that’s the whole point.

Completely local

No SaaS backend. No third-party cloud. Your ledger is a PostgreSQL database on your hardware. Close the laptop and your books close with it.

Free forever

There is no free trial, and no paid tier to graduate to. The license is source-available and permits personal, internal, and enterprise use at no cost.

You own the data

PostgreSQL backups, IIF exports, CSV downloads, PDF statements. Walk away to another tool any time. No lock-in and no contract to exit.

New in v2.23.2, October 2026

QuickBooks Online without the API

Leaving QuickBooks Online takes its own Export data zip and nothing else: the chart, every transaction, the customer and vendor lists, and, with its A/R Aging Detail report beside it, every open invoice and unapplied payment as documents, so the A/R aging is right on day one. No Intuit developer app. And the plumbing for an encrypted company file, contributed by @grungenut. The full release ledger →

  • v2.29.1
    Profit & Loss Detail, Bill Quick Entry, and pre-printed checks. Profit & Loss Detail and P&L totals that open their transactions, the P&L by month or quarter, bills keyed one after another, new accounts from any bill or bank-feed line, pre-printed check stock, and Recent sends for email.
  • v2.29.0
    A mid-year payroll switch, the fiscal year, and reports by item. A fiscal year that starts any month, payroll opening balances for a company that switched mid-year, a pay run that can be voided, Sales and Purchases by Item, Past Customers for a mail list, and a Mercury bank feed.
  • v2.28.0
    Account types and sub-accounts. QuickBooks-style detail types, a Balance Sheet with current and long-term, and sub-accounts nested on the chart and the statements.
  • v2.27.0
    A register you can edit, and a bookkeeper's wish list. Payees and categories added as you type, deposits split with a fee line, entries that open for editing, and a dozen of a bookkeeper's asks.
  • v2.26.0
    Direct deposit from the page, and last year beside this one. A pay run's ACH file from its own page, P&L and Balance Sheet compared to last year, and sessions that end when access changes.
  • v2.25.0
    Several companies on one server. Server Edition serves every company file: the sign-in asks which, a session works in the company it chose, and a one-click switch carries each company's own role.
  • v2.24.1
    Checks from the register, and a ledger export caught. Print Check for a check written in the bank register or as an expense; a QuickBooks ledger export with an added Account column refused, not read as sales.
  • v2.24.0
    Working with your accountant. An Accountant role and invitation, adjusting entries, Closing Date Exceptions, the Accountant's Package, the QuickBooks Desktop round trip both ways, an Accountant's Copy, Reclassify Transactions, open screens, a categorized bank sheet, company file encryption.
  • v2.23.5
    A bookkeeper's first hour. A bank register you can type into, split entries, reconcile through a day, the seeded chart cleaned in one step, the drill-down saved as CSV or PDF, a sidebar you can trim, vendor search and paid-to-date.
  • v2.23.4
    Every QuickBooks Desktop transaction and timesheet. Transaction Detail by Account imports as journal entries, timesheets as time entries, the lists import matches by path and posts opening balances once, and the statements read in the chart's order.
  • v2.23.3
    Voids that always post. A long line memo no longer stops a void, invoices the old QuickBooks Online import counted as paid twice are repaired, and Interoperability says QuickBooks Desktop.
  • v2.23.2
    QuickBooks Online without the API. Its Export data zip migrates a company, open invoices included; the OAuth connector that never reached a real company is gone; the company file can be encrypted.
Nonprofit mode: the Report Center's statement cards (Statement of Activities, Statement of Financial Position, Fund Balances, Statement of Functional Expenses, Pledge Report, Year-End Giving Statements) above the Statement of Activities for 2026 to date compared to prior year: revenue and support $58,970, expenses $36,950, a $22,020 change in net assets against $10,999 the year before, with and without donor restrictions.
Nonprofit mode · new in v2.9

Funds, net assets, functional expenses, donor documents

One switch and the books speak donor, pledge, fund and grant. Funds carry donor restrictions and release from them; every expense knows whether it is program, management or fundraising, with allocation rules for the shared ones; the Statement of Activities, Statement of Financial Position, Fund Balances and Statement of Functional Expenses reconcile to the cent; receipts, acknowledgment letters and year-end giving statements carry the IRS language. Free, for the groups that pay for a "nonprofit edition" of everything else.

Funds & restrictions Form 990 Part IX columns Donor acknowledgments Giving statements
Settings, Users - Server Edition: four users with the roles admin, bookkeeper, accountant and read-only, each with last login, an end date for the sign-in, Deactivate and Reset password, and the form to add a user or invite an accountant.
Server Edition

One office PC serves everyone

Run the signed installer's server mode on one Windows machine and the whole office works in a browser - users with roles (admin, bookkeeper, read-only), username logins, and an audit trail that names who changed what. Starts with Windows, before anyone logs in. Add a second user and you're Server Edition; there's nothing to buy.

Users & roles Attributed audit log Starts at boot Browser clients
Analytics, year to date: revenue $560,465.00, expenses $429,036.40, DSO 58.2 days and a 23.4% margin, then the twelve-month revenue trend line from $42k to $70k with its month-by-month table.
Analytics

Real-time analytics dashboard

KPI cards, 12-month revenue trend, A/R and A/P aging stacks, 90-day cash forecast, expense doughnut. Chart.js self-hosted, no CDN. Period selector for MTD / QTD / YTD. CSV and PDF export with branded headers.

4 KPI cards 5 charts CSV + PDF ~26 ms on 3K invoices
The AI Insights settings card: provider Anthropic Claude, a model picker with claude-sonnet-4-5 typed as the model ID, the API key field, and Test and Save AI settings buttons.
AI Insights

Bring your own AI provider

Eight providers, Anthropic Claude and xAI Grok first, then Groq, Cloudflare Workers AI, a self-hosted Cloudflare Worker gateway, OpenAI, Google Gemini and any OpenAI-compatible endpoint you name. Keys Fernet-encrypted at rest. Eleven predefined analyses spanning customers, vendors, banking, P&L, and tax.

8 providers Encrypted at rest 11 analyses Optional
Items & Services: nine inventory items and four services with rate, cost and quantity on hand (1,240 hinges, 601 sheets of maple ply, 15 quartz slabs), each product with Adjust and History buttons.
Inventory

Perpetual inventory & drill-down

Real inventory ledger with weighted-average cost, automatic COGS journal entries on sale, reorder points, and a low-stock report. P&L and Balance Sheet rows are now click-through to the underlying transactions. Saved reports and fuzzy duplicate detection for customers and vendors.

Perpetual ledger COGS auto-post Drill-down Saved reports
Migrate Data with QuickBooks Online export chosen as the source: upload the Export data zip with the A/R Aging Detail report beside it, then Dry Run or Import.
Integrations

Stripe, PayPal & Square + QuickBooks Online

Accept online payments through Stripe, PayPal, or Square. Enable any combination and the customer pay page shows a button per processor, every payment auto-recorded with a balanced journal entry. Desktop installs record payments too, no webhook required. QuickBooks Online companies migrate from their own Export data zip, no Intuit app needed, open invoices included, and Xero, MYOB, Sage 50, Wave, Zoho Books and GnuCash users migrate in with dry-run verification.

Stripe · PayPal · Square QuickBooks Online export Public pay page Xero migration
The Copperline Woodworks Snapshot split down the middle: the light theme on the left and the dark theme on the right, the same figures, overdue table, bank balances and A/R aging colour key in both.
Accessibility

Readable in both themes, named for screen readers

Text meets WCAG AA contrast in the light and dark themes on every page and dialog, and a browser measures it before each release. Every form field says its name to a screen reader. Every PDF, invoices and tax forms included, is tagged so a screen reader gets headings and tables instead of a picture. Dialogs keep your keyboard focus, and notifications are read out. We strive to conform to WCAG 2.1 AA and say plainly what's still open. Where we stand →

AA contrast, both themes Every field named PDF/UA-1 tagged PDFs Real dialogs Announced notifications
New in v2.5

One product, two ways to run it

Run it on your desktop, or run the same signed installer in server mode and the whole office works in a browser: users with roles (admin, bookkeeper, read-only), username logins, an audit trail that names who changed what, and a startup task that has the books serving before anyone logs in. Add a second user and you've become Server Edition. There's nothing to buy, because there's never anything to buy.

Slowbooks Pro Server Edition with the whole left menu beside the Copperline Woodworks snapshot: receivables, payables, bank balances, A/R aging, monthly revenue, recent invoices and payments, this month's and the year's profit, and the balance sheet trend
Agent-ready

Point your AI at your books

Every install ships a self-documenting 556-operation local API. Built for Claude Code and Grok first; Codex CLI, Gemini CLI or any agentic tool can migrate, configure, and operate your books. The books and the API stay on your machine; the guide says what the agent's own model sees.

The AI setup guide
Demonstration

A full day of bookkeeping, in under a minute

Create an invoice, receive a payment, run a P&L. All the things you’d do in QuickBooks, done locally and without a subscription.

6.3 seconds
From open invoice form to posted journal entry.
SlowBooks Pro 2026 - Create Invoice
Edit Invoice for Harlow Construction on the Ashfield Mudroom job, Net 30, class Wholesale: nine line items from shop fabrication labor and cabinet installation to maple ply, drawer boxes, hinges, slides and a quartz counter slab, totalling $10,691.00.
Posted to journal DR=CR Ready
Local latency < 5 ms
Cloud round-trips 0
Monthly fee $0.00
Data leaves machine Never
Install

Pick your platform

Windows gets a signed installer, macOS gets a signed and notarized native app - download, open, done, no command line. Docker covers Linux, Intel Macs, and container-first servers, with bare-metal source installs for that crowd.

Windows - signed native installer INCLUDES SERVER EDITION

A normal Windows app: download, double-click, done. The installer is code-signed (Windows shows a verified publisher, not a SmartScreen warning) and completely self-contained, so there is nothing else to install.

Download SlowBooksPro-Setup-x64.exe

Currently v2.29.1 for 64-bit Windows 10/11, also available as a portable .zip. Each company is its own file (like QuickBooks company files), stored under %LOCALAPPDATA%\SlowBooksPro, so upgrades and even uninstalls never touch your books. When a new version ships, the app’s footer shows an update notice.

Provenance

A love letter to software that respects you

Owns nothing. Phones home to nobody. Runs on hardware you can unplug. Accounting software should be the last thing you’d rent.

“Intuit’s activation servers died in 2017. The hard drive died in 2024. We just wanted to print invoices.”
Questions

Frequently asked questions

Is SlowBooks really free? What’s the catch?

No catch. SlowBooks is source-available under a license that permits free use for personal, educational, and internal business purposes, including at commercial enterprises. The only restriction is you can’t repackage and resell it as your own paid product or hosted service. See the LICENSE for the full text.

Is it “open source”?

The source is public on GitHub and you can read, modify, and redistribute it. Technically the license is “source-available” rather than OSI-certified open source, because of the No-Commercial-Resale clause. In practice, if you’re using it to run your own business, there is no functional difference.

Why is it not on the cloud?

Because accounting data is the last thing that should live on someone else’s server. Your financial history, customer information, payroll, and tax records shouldn’t be subject to some other company’s pricing decisions, breach history, or terms-of-service updates. SlowBooks sidesteps the entire question.

How do I back up my data?

SlowBooks creates PostgreSQL-native backups on demand from the Settings screen. You can also export everything as IIF (for re-import into QuickBooks), CSV, or PDF. If your computer is already backed up by Time Machine, a cloud drive, or an external disk, SlowBooks’ data is already safe along with the rest.

Does it work on Windows?

Yes, natively. Download the signed installer, double-click, and you’re keeping books in under a minute, without a database server to configure first. Windows shows a verified publisher instead of a SmartScreen warning because every release is code-signed. Each company is a single file under %LOCALAPPDATA%\SlowBooksPro, so backups are as simple as copying a file. Docker still works too, if you prefer containers, and serving your whole office over the LAN needs no Docker at all: that’s Server Edition, built into the same signed installer.

Do I need Docker to run the server / multi-user mode?

No. Server Edition is built into the signed Windows installer. Run it in server mode (or use the bundled install script for a boot-time service) and every machine on your LAN connects through a browser, with per-user logins, roles, and an attributed audit trail. Docker is an optional alternative for Linux servers and Intel Macs, never a requirement. See the Server section or the server setup guide.

Can I import from QuickBooks?

Yes. SlowBooks imports IIF files exported from QuickBooks Desktop (including the finicky Mac QB format with quoted thousands separators). It also has OAuth integration with QuickBooks Online for direct import.

Does SlowBooks really have analytics and AI built in?

Yes. v2.0.0 ships an analytics dashboard (KPI cards, charts, 90-day cash forecast, CSV/PDF export) and an optional AI Insights brief. The AI is bring-your-own-key: pick from eight providers (Claude, Grok, Groq, Cloudflare Workers AI, a self-hosted Cloudflare Worker, OpenAI, Gemini, or any OpenAI-compatible endpoint you point it at). Nothing is sent until you click. Keys are Fernet-encrypted at rest. If you don’t configure a provider, the feature simply isn’t there.

Can my customers pay me online?

Yes, through Stripe, PayPal, or Square (enable any combination). SlowBooks emails invoices with a “Pay Online” button; the customer pays on the processor's hosted page and a balanced journal entry posts back into your local ledger automatically. Card data never touches SlowBooks. Desktop installs record payments on the customer's return, no public webhook needed. The payment URL is a token-scoped page, so customers never need a SlowBooks login.

Is SlowBooks Pro accessible?

We strive to conform to WCAG 2.1 AA. Text meets AA contrast in the light and dark themes on every page and dialog, checked by a browser before each release. Every PDF it makes is tagged for screen readers (PDF/UA-1), invoices and tax forms included. Every form field is announced with its label, and a required field as required. Dialogs keep keyboard focus, and notifications are announced. The full picture, and how to report a barrier →

Is my data secure if it’s all on one machine?

Single-user authentication is built in - setup wizard on first run, argon2id password hashing, rate-limited logins. All API keys you add (AI providers, Stripe, QBO) are encrypted at rest with Fernet. The Docker image runs as a non-root user. v2.0.0 also completed an external security audit pass: SSRF guards on outbound LLM calls, CSV formula-injection protection, schema-validated config payloads, constant-time secret comparison on the Cloudflare gateway. Your books are still on your hardware, same backup story as the rest of your machine (Time Machine, an external disk, whatever you already use).