free · in-browser · no upload
Drop your CSP file. We'll convert it to CUBE right here in your browser, your file never leaves your device.
Select your file here to get started
or drop your file here.
Accepts .csp
How it works
Click the dropzone above or drag a CSP from your desktop. Files of any size, there's no upload, so there's no upload limit.
The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.
Get your CUBE the moment the conversion finishes. Convert another, or close the tab.
Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.
Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.
No account required. No watermark on the output. No queue. Drop a file, get a converted file.
Formats involved
CSP is the Cinespace (Rising Sun Research, now part of Autodesk) LUT format. Text-based with optional 1D preLUT blocks for separate per-channel curves before the 3D mapping, useful for combining tone curves with color grading in one file. Supported by DaVinci Resolve and Lustre.
How to open
DaVinci Resolve, Lustre, Mistika. Plain text in any editor.
CUBE is the Adobe / SpeedGrade color grading LUT format and the most widely supported 3D LUT format in video editing. Plain text: a header declares the grid size (LUT_3D_SIZE 17/33/65), then the body lists RGB triplets in R-major order. Every NLE and color grading tool reads CUBE, DaVinci Resolve, Premiere Pro, Final Cut Pro, FilmConvert.
How to open
DaVinci Resolve, Premiere Pro, Final Cut Pro, Avid Media Composer, OBS Studio. Plain text in any editor.
Related tools
How we compare
| Feature | Ustwineconvert | CloudConvert | iLovePDF | FreeConvert | Smallpdf |
|---|---|---|---|---|---|
| Files uploaded to a server | |||||
| Free file size limit | No limit | 1 GB | 200 MB | 1 GB | 5 GB |
| Free conversions per day | Unlimited | 10/day | Limited | Limited | 2/day |
| Signup required | |||||
| Watermark on output | |||||
| Works offline (after first load) |
Last verified May 2026 from each competitor's pricing and FAQ pages. Limits and pricing change frequently.
FAQ
Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.
Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.
Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.
Color grading workflows that need preLUT + 3D combined. Video color grading, apply a film look or correction LUT. The most common reason to convert is compatibility, CUBE works in places where CSP doesn't, or vice versa.
DaVinci Resolve, Lustre, Mistika. Plain text in any editor.
Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.
Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.