Slim Archiver · v1.0.0 · Windows 10 / 11

High-ratio compression.
Encryption you can verify.

Slim Archiver packs directories smaller with a zstd + LZMA engine, protects them with authenticated XChaCha20-Poly1305 keyed by Argon2id, and gives IT the controls to roll it out — SSO, GPO policy, DLP and audit logging.

Download for WindowsSee pricing

Windows 10 / 11 · 64-bit · Requires AVX2 CPU (Intel 2013+ / AMD 2015+) · silent per-machine installer

XChaCha20-Poly1305Argon2id KDF Entra ID SSOGPO policyDLPAmazon S3Audit log
What it does

The whole engine, nothing paywalled.

Compression, encryption, deduplication and multi-format extraction are all in the free tier. Paid tiers add packaging and enterprise governance — never the core.

High-ratio compression

A zstd + LZMA pipeline with solid archives and BCJ/delta filters. Every method -m1–-m6 is included free — nothing about the engine is paywalled.

Authenticated encryption

XChaCha20-Poly1305 keyed by Argon2id, with block headers bound as AAD so tampering is detected on extraction. Optional encrypted filenames.

Global deduplication

Content-defined chunking finds data that repeats across files and stores it once — large wins on backups and versioned trees.

Reads what you have

Extracts .slim, .zip, .rar, .tar, .gz and .tgz — one tool for the archives you already own.

Parallel by design

Multi-threaded compression and extraction. On an 8-core / 16-thread laptop it compresses ~1.5–2× faster than 7-Zip and extracts many-file archives 3–4× faster.

Enterprise controls

SSO with Entra ID, GPO policy, DLP, Amazon S3, Smart-Card / CAC, audit logging, password-vault integration and Outlook “Zip & Send.”

Benchmarks — measured on public corpora

Measured, not marketed.

Every number is from a real run you can reproduce — no illustrative estimates. Where 7-Zip or WinRAR still wins, we show it.

46% smaller

On versioned / redundant data

Two Linux kernel versions in one archive: 135.1 MiB vs 7-Zip’s 249.8 MiB — and extracted 4.5× faster.

~4× faster

Extraction on many files

The kernel and real-world sets extract in ~14–17s where 7-Zip takes ~67–76s and WinRAR ~52–65s. Compression at -m6 runs ~1.3–1.7× faster than 7-Zip -mx9 too.

~1–3% behind

Ratio against 7-Zip

With the same 64 MiB dictionary, 7-Zip -mx9 still compresses smaller than Slim -m6: 1% on unrelated source trees (172.7 vs 174.7 MiB) and 3% on text (enwik9: 204.8 vs 211.1 MiB), taking 1.3–2.6× as long. Shown because a benchmark you can’t trust is worthless.

ToolArchiveSavedCompressExtract
Silesia Corpus (202.1 MiB, mixed)
Slim -m161.6 MiB69.5%0.5s0.2s
Slim -m354.8 MiB72.9%3.6s0.2s
Slim -m448.2 MiB76.1%5.3s0.7s
Slim -m646.6 MiB77.0%16.3s1.5s
WinRAR -m550.7 MiB74.9%3.6s0.4s
7-Zip -mx9 -md64m46.5 MiB77.0%30.2s1.1s
ZIP -mx961.7 MiB69.5%19.4s0.7s
enwik9 (953.7 MiB, text)
Slim -m1296.2 MiB68.9%1.9s1.1s
Slim -m3247.3 MiB74.1%12.6s1.1s
Slim -m4231.2 MiB75.8%31.6s2.1s
Slim -m6211.1 MiB77.9%52.9s6.0s
WinRAR -m5221.7 MiB76.8%25.1s1.9s
7-Zip -mx9 -md64m204.8 MiB78.5%135.7s2.0s
ZIP -mx9296.3 MiB68.9%353.3s3.5s
real-world (1833.4 MiB, mixed source)
Slim -m1257.8 MiB85.9%4.4s13.7s
Slim -m3210.8 MiB88.5%12.7s13.8s
Slim -m4185.9 MiB89.9%34.4s14.2s
Slim -m6174.7 MiB90.5%67.3s14.6s
WinRAR -m5214.1 MiB88.3%68.1s52.1s
7-Zip -mx9 -md64m172.7 MiB90.6%86.8s66.9s
ZIP -mx9367.9 MiB79.9%96.6s69.5s
Kernels (2523.2 MiB, 2 versions · dedup)
Slim -m1201.8 MiB92.0%4.7s15.9s
Slim -m3163.6 MiB93.5%11.8s16.0s
Slim -m4143.5 MiB94.3%31.8s16.1s
Slim -m6135.1 MiB94.6%69.4s16.7s
WinRAR -m5175.0 MiB93.1%75.5s64.9s
7-Zip -mx9 -md64m249.8 MiB90.1%115.2s75.9s
ZIP -mx9498.6 MiB80.2%138.0s79.8s
Cyan = best in that column for the corpus (whichever tool wins). Lower is better for size and time; higher for % saved. Archive size (MiB) is the ground truth. Slim -m2 and -m5 lie between their neighbors in archive size and compression time.

Dictionary (match window): Slim -m1 and -m2 use each block as the window (blocks of up to 16 MiB and 64 MiB, compressed independently); -m3 to -m6 use 64 MiB. WinRAR 64 MiB (-md64m), 7-Zip 64 MiB (-md64m; without it, -mx9 uses a larger default), ZIP 32 KiB (fixed by the Deflate format).

Measured on a Lenovo Legion 5 Pro — AMD Ryzen 7 8745HX (8C/16T), 32 GB DDR5-5200, NVMe SSD, Windows 11 Pro. Runs of October 2026 · Median of 3 runs · Defender real-time scan off · AC power.

All times were measured with each tool’s command line (slimarch.exe for Slim Archiver). The desktop app runs the same engine; its times can be somewhat longer, and with Data Loss Prevention enabled (Enterprise) every file is scanned before it is compressed, which adds time.

Command line

Scriptable, everywhere.

The same engine as the app, from the terminal — ideal for backups, CI and servers.

slimarch — common commands
create$ slimarch c out.slim ./dir -m6
encrypt$ slimarch c out.slim ./dir -m6 -p<pass>
encrypt+names$ slimarch c out.slim ./dir -p<pass> -en
extract$ slimarch x out.slim -o"./restore"
list / test$ slimarch l out.slim  |  slimarch t out.slim
self-extract$ slimarch c out.slim ./dir -sfx # Pro
split$ slimarch c out.slim ./dir -v700m # Pro
Pricing

Free where it counts.

The compression and encryption engine is free forever. Pay only for packaging and enterprise governance.

Free
$0
  • All compression methods -m1–-m6
  • Solid archives, BCJ/delta filters
  • Global deduplication
  • XChaCha20-Poly1305 encryption
  • Extract .slim / .zip / .rar / .tar / .gz / .tgz
  • Desktop app & command line
Download
Pro
$25 $20 / one-time
  • Everything in Free
  • Self-extracting (SFX) archives
  • Multi-volume / split archives
  • Perpetual license — all v1.x updates included
Buy Pro
Enterprise
Custom
  • Everything in Pro
  • SSO (Entra ID) & GPO policy
  • DLP & audit logging
  • Amazon S3 & Smart-Card / CAC
  • Password vaults & Outlook Zip & Send
Contact sales

Introductory launch price: $20 (regularly $25) for the first 3 months, through [[ INTRO END DATE — launch + 3 months ]]. Pro is a perpetual license covering all v1.x updates; v2.0 is a separate paid upgrade — but buy within the 90 days before v2.0 ships and you're upgraded to it free.