How UltKit works

1. Choose the tool and add your file

Pick a tool from the menu or from a search result. Each page is a single job, for example compress a PDF to 200 KB or convert HEIC to JPG, and the main options for that job are already filled in. Drag a file onto the upload area, click it to browse, or paste an image from the clipboard. Most tools accept several files at once.

Files never leave your device until you have chosen them, and a file that is the wrong type or too large is rejected in the browser before anything is uploaded.

2. Adjust the options

The settings that matter for the job sit next to the file list: target size, dimensions, output format, quality. Advanced settings are collapsed below them and only needed for unusual cases. The defaults are chosen per page, so a passport photo page starts with the right dimensions and background, and a Discord video page starts with the 10 MB cap.

3. Convert

When you press the button the file is sent over HTTPS to our processing servers, where open-source engines (ImageMagick, libvips, Ghostscript, FFmpeg, LibreOffice, Tesseract and others) do the work. Processing is done on the server rather than in your browser so that large files, heavy formats and multi-file batches behave the same on a phone as on a desktop.

4. Download, then we delete

The result appears as a download link, one per file or a single ZIP for a batch. Both the original upload and the converted output are deleted automatically 30 minutes after processing finishes. Download links stop working at that point. There is no account and no history, so if you need the file again later, convert it again.

Security and privacy

• Transfers use HTTPS end to end; storage is isolated per job and not shared between users.
• Files are processed by software only. No person reads them, and they are not used for analytics, advertising or model training.
• We log the technical minimum needed to run the service: time, tool, file type and size, and the requesting IP address for abuse prevention. Logs are kept for up to 30 days. File contents are never logged.
• The full detail, including analytics and advertising cookies, is in the privacy policy.

Limits

• Each tool page states its maximum file size and file count next to the upload area; the limit is 95 MB per file on every tool.
• Processing time depends on the file: images and PDFs usually take seconds, long videos can take a few minutes.
• Password-protected files must be unlocked first; the Unlock PDF tool does that when you know the password.
• We do not fetch files from URLs. Everything you convert must come from your own device.

Formats

UltKit handles the common formats and many uncommon ones: JPG, PNG, WebP, HEIC, AVIF, GIF, TIFF, BMP, SVG, camera RAW (CR2, NEF, ARW, DNG), PDF, DOCX, XLSX, PPTX, Pages, EPUB, MOBI, MP4, MOV, MKV, WebM, MP3, WAV, M4A, FLAC, ZIP, RAR, 7z, TTF, WOFF, SRT, VTT, DWG, DXF, STL and more. Every conversion page explains the input and output format, when to use each and what changes in the conversion.