What it is, who put it there, and whether it’s safe to delete. Strata reads the NTFS Master File Table directly and keeps every view live as files change.
The demo needs JavaScript.
Hover for details, double-click a folder to open it, Ctrl + scroll to zoom. Tab into the window to use the keyboard; Esc returns to the page.
Best viewed on a desktop. On small screens the window is scaled down to fit and doesn’t respond to touch.
This window runs Strata’s own interface, built from the same code as the desktop app, on a generated sample volume of 4,000 entries. The maps are laid out in your browser by a port of the app’s layout engine that produces the same bytes. Scanning, insights, cleanup, history and settings need the desktop app, so they show as unavailable.
01What it does
A disk map tells you something is big. Strata tells you what it is, which app made it, and whether removing it is safe.
Reads $MFT directly instead of walking folders, with exact sizes for hardlinks, streams, compression, sparse files and cloud placeholders.
Tails the USN change journal and patches the index in place, so every view stays current without a rescan.
Live updates240 built-in rules name the category, owning app and safety tier for each path, and show which rule matched.
Rule packsA never-delete list in code, re-verification by file id right before acting, Recycle Bin by default and one-click restore.
Deletion safetyName search with filters like *.gguf size:>1gb. First results in ≤ 1.1 ms over 5 million names.
Snapshots show what grew since the last scan. The duplicate finder skips hardlinks and never downloads cloud-only files.
History and duplicatesOpt-in ETW tracing shows which program is writing what, aggregated per folder and per hour.
Activity trackingTreemap, sunburst, icicle, circle packing and mind map, laid out in Rust and drawn with WebGL2 at a steady frame rate.
Views02Benchmarks
Every figure comes from Strata’s own benchmark suite and is reported as the spread across runs, not the best one. Each says what was measured and on what kind of data.
Measured on an 8-core/16-thread desktop CPU, NVMe SSDs, mid-range discrete GPU, Windows 11.
Complete scans of the same volume on the same machine, timed from launch to a full size total.
| Tool | Full scan, system volume (lower is better) | Note |
|---|---|---|
| Strata (MFT) 0.1.0 | 26.2 s | |
| WizTree 4.28 | 86 s | |
| Windows File Explorer | 560 s |
| Tool | Peak memory, system volume (lower is better) | Note |
|---|---|---|
| Strata (MFT) 0.1.0 | 918 MiB | |
| WizTree 4.28 | 2,857 MiB | |
| Windows File Explorer | Not measured |
With admin rights, Strata reads the drive’s Master File Table directly. Without them, a parallel folder scanner fills the same index.
155–291ms
to parse a million file records from the Master File Table
All cores, 3.4–6.4 million records per second. This is parsing speed: reading the table off the drive adds disk time.
In-memory NTFS images
20–23s
per million files without admin rights
Standard scanner with exact on-disk sizes, on a real system volume of about 4.6 million entries. A generated 1-million-file tree takes 13.2 s.
Real system volume
| Measurement | Result |
|---|---|
| All cores, fixups, parse and assemble in parallel | 155–291 ms |
| One thread, same work, single core | 0.64–1.02 s |
Search, the largest-files list and folder listings answer from the in-memory index, never from the disk.
≤ 1.1ms
to the first search results across 5 million file names
The complete pass finishes in ≤ 28 ms for every query type tried: substring, prefix, wildcard, path, regex and filters.
Synthetic index
0bytes
read from disk when re-checking duplicates
Unchanged files are answered from the hash cache in under 1 ms. Fresh hashing runs at 2.7, 4.4 and 5.6 GB/s on 1, 2 and 4 threads with data in the OS cache.
Synthetic files
| Measurement | Result |
|---|---|
| First search results, 5M names, any query | ≤ 1.1 ms |
| Open a 100,000-item folder, largest 200 first | 8.0 ms |
| Top 100 largest files, 5M entries | 12.2 ms |
| Complete search pass, 5M names, slowest query type | ≤ 28 ms |
Strata follows the NTFS change journal, so open views update in place instead of rescanning.
251–265ms
from a file changing on disk to an updated view
Change-journal record to the change set the UI applies, end to end.
Live-update benchmark
1.9s
to absorb 500,000 files created at once
The slowest UI tick during the burst took 66 ms and the index was never locked for more than 24 ms. Sustained intake is about 316,000 journal records per second into a 1-million-entry index.
Live-update benchmark
| Measurement | Result |
|---|---|
| One change, disk to view, journal record to UI change set | 251–265 ms |
| Longest index lock, during the 500k burst | 24 ms |
| Slowest UI tick, during the 500k burst | 66 ms |
| Whole burst absorbed, 500,000 new files | 1.9 s |
Maps draw on the GPU from layout buffers computed in Rust, so hovering, zooming and drilling stay smooth on very large folders.
100fps
with 503,464 blocks on screen and no dropped frames
Hover, zoom and pan sweeps; frame time p95 10.1 ms, p99 10.2 ms. Headless Chromium paces frames at 100 Hz, so 100 fps is the ceiling of the measurement, not of the renderer.
Headless Chromium, real GPU
| Measurement | Result |
|---|---|
| Find the block under the cursor, 503k-block map | 0.12 µs |
| Hover, end to end in the UI, including DOM measurement | 18–26 µs |
| Re-lay out a folder, 100,000 items | 3.2 ms |
| Lay out a whole treemap, 1 million entries | 6.8 ms |
| Frame time, p99, 503,464 blocks | 10.2 ms |
A small native app that holds the index compactly and sleeps while nothing changes.
59.2B
of memory per file, plus its name
At 5 million entries; 58.7 B at 1 million. Names average 16.5 bytes in the test data.
Synthetic index
~3MB
installer download
The x64 installer package.
Release build
0wake-ups
while idle
No CPU wake-ups in a 3-second idle window. Optional activity tracking costs about 1.1% of one core at 10,000 events per second.
Live-update and activity benchmarks
| Drive size | Index, 58.7–59.2 B per entry | Names, 16.5 B average | Total |
|---|---|---|---|
| 1 million files | 58.7 MB | 16.5 MB | 75.2 MB |
| 5 million files | 296 MB | 82.5 MB | 378.5 MB |
| 10 million files (estimated) | 592 MB | 165 MB | ≈ 0.76 GB |
cargo bench -p strata-ntfs --bench parsecargo run --release -p strata-cli -- scan C:cargo run --release -p strata-walk --example walkbench -- <root> [dirinfo|find] [alloc 0|1] [threads]cargo run --release -p strata-walk --example mktree -- <root> 1000000cargo bench -p strata-indexcargo bench -p strata-layoutcargo bench -p strata-livecargo bench -p strata-dupescargo bench -p strata-etwpnpm --dir ui fixtures:large
pnpm --dir ui dev
node ui/scripts/run-harness.mjs large treemappowershell -ExecutionPolicy Bypass -File bench\verify-elevated.ps103Architecture
Privileged work happens in a small helper behind a locked-down named pipe. Without it, a standard scanner feeds the same index.
Hover or focus a layer to see what it does.
04Download
Free for Windows 10 22H2 or Windows 11. Pick the installer for your processor; if you’re not sure, it’s x64.
Most Windows PCs, with Intel or AMD processors.
Download for x64Windows on ARM, such as Snapdragon laptops.
Download for ARM64The installers aren’t code-signed yet, so Windows SmartScreen may ask you to confirm. Installed copies update themselves, and every update is verified against the project’s signing key.
939c707229103a6c139545de998e1197f108adcd20c47e32ed3f46599b7feab9c3936301b88d2a80d49a141561eb32cd6a6f642ac447d5a7fa85474ab4196c1eCheck a download in PowerShell with Get-FileHash .\Strata_0.1.0_x64-setup.exe and compare the hash.
No telemetry. Everything stays on your machine.
Scans, history, settings and the undo log stay local. The app only contacts GitHub Releases to check for, download or roll back updates; the installer may fetch Microsoft’s WebView2 runtime, and “Report an issue” just opens your browser.
Free, open source, and native to Windows.