Disk space analyzer for Windows
See what’s eating your disk. Reclaim it in minutes.
Scan any drive in seconds, see exactly what’s using your space, and delete it safely from one view. Every rectangle is a file; its area is the space it takes up.
An illustration, drawn to scale from a real C:\ scan. Screenshots of the app are below.
The problem
Your C: drive is full and Explorer won’t tell you why.
Windows tells you how much space is left. It won’t tell you what took it. Finding the culprit by hand means opening folder after folder, checking properties, guessing. Tessera does it in one pass.
A map, not a spreadsheet
The big files are simply the biggest things on screen.
Tessera draws your disk as a treemap: every file is a rectangle, and its area is proportional to its size, colour-coded by file type. You don’t have to read anything to find them.
A size-sorted folder tree sits alongside, and the two stay in sync both ways. Click a block and the tree jumps to it; select a folder and the map highlights it. Double-click to drill in, one button to come back out.
Built to be used
Fast, and honest about what it shows you.
A disk map that quietly leaves things out is worse than no map at all, because you will act on it.
Fast enough to actually use
One worker per CPU core over a shared queue, reading sizes straight from the directory entries rather than opening every file. A million files take seconds, and you can cancel any time and keep the partial result.
Links shown, never followed
Junctions and symlinks are displayed but never followed, so nothing is counted twice and no loop can hang a scan.
Locked folders are flagged
Folders Windows won’t let it read are flagged and counted, rather than quietly appearing empty. A drive or share it can’t reach says so.
Never a partial picture
Every detail level draws the whole disk. Turning detail down makes the blocks chunkier; it never leaves gaps.
Delete with confidence, not hope
Deleting should never be the scary part.
Tessera confirms every deletion with the full path and size in front of you, and sends files to the Recycle Bin, not oblivion.
Network shares have no Recycle Bin, so there the menu says Delete permanently and the dialog spells out that it cannot be undone, rather than promising a safety net Windows will not provide. Rescan a single folder after a clear-out and the totals re-propagate to the root without re-reading the drive.
Illustrations of what the confirmation tells you.
Or skip the map
Take the top 100.
Sometimes you already know you just want the big files gone. Top 100 lists the largest individual files under whatever you are looking at, biggest first, with the full path beside each one — so you can see at a glance which are yours and which belong to something you installed.
Network drives too
Map a NAS the way you map a local disk.
Point it at \\server\share — typed into the toolbar, passed on the
command line, or mapped to a drive letter. The scanner raises its concurrency for
network latency, because over SMB the time goes on round trips rather than CPU.
For scripts and servers
Print totals and exit without opening a window, with proper exit codes for automation.
Everything it does
One tool, one job.
- Squarified treemapFile size becomes rectangle area, coloured by type
- Two-way syncTreemap and folder tree always agree
- Parallel scannerOne worker per core over a shared queue
- Recycle Bin deleteConfirmed with full path and size; told plainly when a share makes it permanent
- Network sharesScan \\server\share or a mapped drive, tuned for SMB latency
- Single-folder rescanNo full re-scan after a clear-out
- Top 100 largest filesThe quick wins, in one list
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Headless CLI
--scanfor scripting, with real exit codes - PortableOne file, no installer, no runtime, no telemetry
One-time purchase
Find the big files. Delete them safely. Move on.
£2.99+
Pay what you want, from £2.99. No subscription, no account, no expiry.
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One self-contained
Tessera.exe, about 102 MB - Nothing installed, nothing written outside its own folder
- No telemetry — no data leaves your machine
- Windows 10 and 11
Before you buy
Questions
Does it install anything?
No. It is one self-contained executable: nothing is installed, no runtime is required, and nothing is written outside the app’s own folder. Copy it to a USB stick and run it on any Windows 10 or 11 PC.
Windows says “Windows protected your PC”.
That is SmartScreen. The executable is not code-signed, so Windows warns on first run. Click More info, then Run anyway.
Can I undo a delete?
On a local drive, yes: files go to the Recycle Bin. Network shares have no Recycle Bin, so there the delete is permanent — and Tessera says so, in the menu and in the confirmation, before anything happens.
Why do some folders show as unreadable?
Windows keeps some folders from ordinary users. Tessera flags and counts them rather than showing them as empty, so the map never pretends to be more complete than it is.
Is it a subscription?
No. It is a one-time purchase: no subscription, no account, no expiry.
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