Select folder or files
Click to browse folder contents (webkit-supported browsers)
For the best visualization, select a folder. We will map the hierarchy based on the relative paths. Block size represents the relative file size.
What is the Folder Size Visualizer?
The Folder Size Visualizer is a client-side disk space diagnostic tool that generates an interactive treemap of your directory structure. By uploading a local folder, you can visualize how much space individual files and subfolders occupy, helping you identify heavy directories at a glance.
Rather than using text list directories, this tool represents sizes as proportional colored blocks (treemaps). Because all file scanning and graphics rendering occur locally in browser RAM, your file naming conventions, folder structures, and system details remain completely private.
How to Use the Folder Size Visualizer
- Select Your Directory: Click the "Select Folder" button to launch your system's directory picker. Choose the folder you want to analyze and confirm read permissions.
- Wait for Local Indexing: The tool scans the directories, calculating file size proportions and mapping extension colors.
- Analyze the Treemap: Examine the generated block diagram. The size of each rectangular block represents the file's space footprint, while the colors indicate the file categories shown in the legend.
- Inspect File Details: Hover your cursor over any block to display a tooltip showing the file name, directory path, and exact file size.
Key Features
- Proportional Block Mapping: Renders folder structures as a nested treemap where block area indicates file size.
- Dynamic Extension Legends: Color-codes blocks automatically by category (e.g., green for media, orange for documents) for easy scans.
- Hover Information Tooltip: Displays real-time details (filename, path, byte size) on mouse hover.
- Recursive Folder Traversing: Scans all subfolders inside the selected directory to build a complete size map.
- Offline Data Isolation: Renders visual treemaps without uploading directory lists or data to external servers.
Common Use Cases
- Developer Node Module Audits: Scan project directories or
node_modulesfolders to identify heavy code packages. - Video and Photo Library Sorts: View which raw footage files or image exports are occupying the most disk space on backup drives.
- System Cache Decluttering: Map hidden application folders or temporary cache files to clear disk space.
- Document Directory Overviews: Inspect corporate directories to check if archived spreadsheets or PDFs need to be compressed.
Frequently Asked Questions
No. 99tool.in processes all directory indexing locally. The files are parsed inside your browser session to extract size metadata; no file content is read, and no data is sent to our servers.
Modern browser security models require explicit permission before web scripts can index local folder contents. Confirming the prompt allows the browser to read file sizes locally for the treemap calculations.
The visualizer can process directories containing thousands of files. For extremely large folders (e.g., full system disks containing millions of files), browser memory limits may cause the tab to lag or crash.
No. This is a read-only visualizer. Due to browser sandboxing, the tool cannot write to or delete files from your system. You can locate and delete files manually on your computer.
Most modern desktop browsers (Chrome, Edge, Brave, Safari) support directory webkit-uploads. If your browser does not support folder uploads, you can select multiple files to see their relative size distribution.
🔒 Privacy & Data Note: Directory mapping and treemap rendering occur locally in your browser. No filenames, structures, or paths are sent to our servers. Last updated: April 10, 2026.