TRTT vs PSPP: Two Free SPSS Look-Alikes Compared

Choose PSPP if you want a mature, fully open-source desktop program with the widest free coverage of SPSS syntax, including DO IF, AGGREGATE and MATCH FILES. Choose TRTT if you want SPSS 32-style menus with nothing to install, in a desktop browser or as a native app on iPad and iPhone, and procedures PSPP doesn't have yet, such as TwoStep and hierarchical clustering, discriminant analysis and the Chart Builder.

Both are free on the desktop, both open and save .sav files, and both understand SPSS syntax. This comparison is written by the TRTT team. PSPP is also the reference we test TRTT's numbers against, so we know it well and respect it. Facts about PSPP come from its official site and manual (version 2.1.2, released September 2026), checked in October 2026.

Short answer

Where each one runs

PSPP is a desktop program. On Linux it's in the standard repositories (apt-get install pspp, dnf install pspp) and on Flathub. Windows has installers from the project. On macOS there are three routes: an application bundle, MacPorts or a Homebrew tap. Mac users sometimes find that the ready-made bundle trails the newest release, so if you need the latest version on a Mac, Homebrew is usually the way. PSPP has no official online version; "PSPP online" in practice means running it on a remote desktop.

TRTT runs in a desktop browser at trtt.app. You open the page and start working; there is no installer and no account. The engine runs inside the browser, so the data stays on your computer. The web version is built for desktop browsers and isn't designed for phone screens. On iPhone and iPad there is a native app (iOS and iPadOS 17 or later) that opens .sav files from Files and Mail. There is no Android app.

If "PSPP for Mac" has been a headache for you, the browser version of TRTT is a way around installing anything. If you work on Linux, PSPP is the natural choice.

Interface

PSPP's graphical interface, PSPPIRE, gives you a data editor with data and variable views, dialog boxes for its procedures, a syntax editor and an output window. Its menus cover the procedures PSPP implements, so they are shorter than SPSS's.

TRTT copies the layout and names of the SPSS 32 Analyze menu on purpose, so muscle memory carries over. For example, t tests and One-Way ANOVA sit under Analyze ▸ Compare Means and Proportions, as they do in current SPSS. Data View, Variable View, the Syntax window and the Output window work the way SPSS users expect. Every dialog has a Paste button that writes SPSS syntax and also equivalent R and Python code (equivalent in what it computes, not always in how the output looks).

Procedures

Both cover the everyday core: frequencies, descriptives, explore, crosstabs, means, t tests, one-way ANOVA, univariate GLM, correlations, linear regression, factor analysis, K-means clustering, reliability (Cronbach's alpha) and the classic non-parametric tests.

Only in PSPP: logistic regression, custom tables (CTABLES), ROC curves and the MATRIX language.

Only in TRTT: TwoStep Cluster, hierarchical clustering, discriminant analysis, nearest neighbour classification, ordinal regression (PLUM), Ratio statistics, multiple response tables, Replace Missing Values and the Chart Builder. PSPP's manual lists most of these under "not implemented"; nearest neighbour isn't mentioned at all.

In neither: mixed models (MIXED) and repeated-measures GLM. If you need those, look at jamovi, R or SPSS itself.

Syntax coverage

This is where PSPP is clearly ahead. Its language includes DO IF, LOOP, DO REPEAT, DEFINE macros, AGGREGATE, ADD FILES, MATCH FILES and UPDATE. If your .sps files restructure data, merge files or loop over variables, they have a much better chance of running in PSPP.

TRTT runs procedures, transformations and labels from .sps files: the procedures above plus COMPUTE, RECODE, COUNT, RANK, AUTORECODE, SHIFT VALUES, RMV, SELECT IF, FILTER, SPLIT FILE, WEIGHT, SORT CASES and the dictionary commands (VALUE LABELS, MISSING VALUES, FORMATS, RENAME VARIABLES, ALTER TYPE and others). It does not yet support DO IF, IF, LOOP, DO REPEAT, variable ranges with TO, AGGREGATE, MATCH FILES, ADD FILES, GET FILE, SAVE OUTFILE, LOGISTIC REGRESSION, CTABLES, MIXED, macros or BEGIN PROGRAM; data files are opened and saved through the File menu instead. TRTT's advantage is that you can run syntax in a browser tab, with no install: see run SPSS syntax online for the full list.

Files

Both keep the metadata that matters: variable and value labels, missing values, formats and measurement levels. TRTT also preserves multiple-response sets, long variable names, very long strings and custom attributes when it saves.

Charts and output

PSPP draws scatterplots, histograms and bar charts with the GRAPH command, plus charts from procedures such as histograms and pie charts in FREQUENCIES and plots in EXAMINE. It writes output as text, PostScript, PDF, HTML and OpenDocument, and from the command line it can also write .spv files.

TRTT has a Chart Builder and the legacy Bar, Line, Pie, Histogram and Scatter/Dot dialogs, with charts drawn the same way on web and iOS. On the web you can export the whole output as .spv, save charts as images and copy tables into Word or Excel. There is no PDF export on the web; the iOS app exports PDF.

Price and licence

PSPP is free software under GPLv3 or later: no fees, no expiry, and you can read and change the code. Its site says it supports over a billion cases and over a billion variables.

TRTT's web version is free, with no paid plan. It is not open source. It sends anonymous feature-usage counters, which contain nothing from your data and are switched off by Global Privacy Control or Do Not Track. The iOS app is free with every feature on data sets up to 100 cases; a larger file can be loaded as its first 100 cases or opened in full with TRTT Pro (weekly or monthly subscription, or a one-time purchase; prices are shown in the app). The iOS app sends no telemetry.

Verdict by situation

• You're on Linux, or you want open-source software: PSPP.
• Your syntax uses DO IF, AGGREGATE, MATCH FILES or macros: PSPP.
• You need logistic regression or custom tables for free: PSPP.
• You can't or don't want to install anything (shared computer, locked-down laptop): TRTT in the browser.
• Your course follows SPSS 32 menus and you want the same paths: TRTT.
• You need TwoStep, hierarchical clustering, discriminant analysis or the Chart Builder: TRTT.
• You work on an iPad or iPhone: TRTT's app; SPSS for iPad explains the 100-case free tier.

Many people will happily use both: PSPP for heavy syntax jobs on the desktop, TRTT for quick work in a browser or on a tablet. For the full field, including jamovi and JASP, see SPSS alternatives compared, and for PSPP against the original, PSPP vs SPSS.

Try it: Open TRTT in your browser – free · Get TRTT for iPhone & iPad

FAQ

Is there a free alternative to PSPP?

Yes. TRTT is free in a desktop browser and also follows SPSS menus and syntax. jamovi and JASP are free too, but they use their own interfaces and don't run SPSS syntax.

Is there an online version of PSPP?

There is no official one; PSPP is a desktop program. If you want SPSS-style syntax and menus in a browser, TRTT runs there without installation, though it supports fewer syntax commands than PSPP.

Which is closer to SPSS, PSPP or TRTT?

It depends on what you mean. PSPP is closer in syntax coverage. TRTT is closer in menu layout (it mirrors SPSS 32) and covers some procedures PSPP lacks. Neither is identical to SPSS.

How do I get PSPP on a Mac?

The PSPP site lists three routes: an application bundle, MacPorts or a Homebrew tap. If installing is a problem, TRTT runs in Safari or Chrome on a Mac with nothing to install.

Can both open the same .sav files?

Yes. Both read and write .sav with variable labels, value labels and missing values. PSPP also handles .por portable files; TRTT doesn't.

TRTT is an independent product. It is not affiliated with or endorsed by IBM. IBM and SPSS are trademarks of International Business Machines Corporation.