Time as the unit
Instead of levels 1 to 9, one question: how much time to spend. TSR measures your machine and your files, picks the strongest method that fits and tells you duration, space and extraction time before it starts.
How it calibratesTime Space Reducer · free beta 0.10.2
TSR takes already-compressed files apart, compresses the real data and puts them back byte for byte. Choose how much time to give it: before it starts, it tells you how long it will take and how much space the archive will need.
macOS on Apple Silicon · Windows 10 and 11 · Linux x86-64 and ARM64 — free until 31 January 2027
Office documents · 1,322 files, 199.5 MB
47.888%
Office documents
First among ten tools; the best of the others: 51.98%
−18.2%
JPEG photos
Given back bit-identical, where general archivers gain nothing
3
Architectures, same bytes
Apple Silicon, x86-64 and ARM64 write the same archive
1–30%
Parity, if you want it
The archive repairs itself, even encrypted and without the password
The method
Instead of levels 1 to 9, one question: how much time to spend. TSR measures your machine and your files, picks the strongest method that fits and tells you duration, space and extraction time before it starts.
How it calibratesPDF, Office, PNG, JPEG and video already contain a compression layer, which zip and 7-Zip see as noise. TSR takes it apart, compresses the real data and puts the layer back byte for byte, checked file by file.
The ten file familiesThe archive browses like a folder: preview, search, extraction of a single file. It mounts in Finder or File Explorer, and a film plays from inside the archive, which stays compressed.
The three doorsThe numbers
Five folders that resemble real ones, compressed by TSR and by the best of ten tools. The size of a TSR archive depends only on the files and the profile: redone on another machine, it gives the same bytes.
| What | Best rival | TSR | Difference |
|---|---|---|---|
| Office documents (1,322 files) | 51.98% | 47.888% | 4.1 points |
| Medical images and reports | 45.47% | 34.71% | 10.8 points |
| Phone photos and videos | 97.41% | 83.76% | 13.7 points |
| Graphics: PNG, TIFF, fonts | 79.61% | 69.51% | 10.1 points |
| PDFs, slides, photos, lectures | 74.71% | 69.39% | 5.3 points |
Where TSR is behind, we say so with the same precision. On pure text zpaq, bsc and PPMd make smaller archives; on tens of thousands of small files, such as source code and mail, 7-Zip in solid mode leads by 2–7 points: the price of an archive that opens at any point.
Reliability
A hundred thousand lines in a language that rules out the most exploited defects by construction; 18 fuzzing targets, 11.77 million executions, zero defects; a format with an executable specification.
Security and privacyWho it is for
Photos, documents, projects and backups on macOS, Windows and Linux, with an application you use by dragging a folder. Less space on disk and in the cloud, and an archive that opens like a folder.
Quick startHealthcare, law firms, publishing: archives to keep for years, to verify years later and to repair without the password. On medical images and reports TSR is 10.8 points below the best of the others.
The usage scenariosCommand line with JSON output, HTTP and WebDAV service, daemon with a job queue, C library, Linux packages and containers. The version for companies works inside your network, with no communication to the outside.
TSR for businessThis site works without cookies, keeps no record of who visits and loads nothing from other servers: fonts and images come from here. Nobody counts the downloads.
The beta sends crash reports and usage metrics only if you turn them on, and never file names, paths or contents. The data stays ninety days on a server in the European Union, and you delete it yourself whenever you like.
The diagnostics privacy noticeBeta 0.10.2 is free until 31 January 2027. The archives you create open forever, even after the beta ends.