How Our Tools Work

Two kinds of tools

Browser-side tools — word counters, JSON formatters, calculators, generators — run entirely in your browser. Nothing you type or paste leaves your device. If you turned off your internet connection after the page loaded, most of them would keep working.

File converters need real conversion engines, so those run on our servers. Your file is uploaded over an encrypted connection, converted, handed back to you, and deleted. The rest of this page is about these.

The engines

We don't write our own PDF parser or audio codec — nobody should. The conversions run on the same open-source engines that power much of the industry, and each tool page names the engine it uses:

• •LibreOffice handles document conversions: Word, Excel, PowerPoint, ODF, RTF.
• •FFmpeg handles audio and video: MP3, WAV, FLAC, OGG, MP4, and the rest.
• •Ghostscript and pdfplumber handle PDF work: rendering, compression, table extraction.
• •ImageMagick handles images: PNG, JPG, WebP, AVIF, HEIC.
• •Tesseract handles OCR when text needs to be read out of images.
• •Calibre handles ebook formats like EPUB and MOBI.

Using known engines has a practical benefit for you: their behaviour is documented, their edge cases are known, and when a tool page here says "merged cells may shift", that warning comes from how the engine actually behaves — not from guesswork.

The queue

Conversions don't run the instant you click convert — they enter a processing queue, usually for just a second or two. The queue exists so one person converting a 200 MB video can't slow down everyone converting invoices. It also means large files convert reliably instead of timing out halfway.

This is also why tools have size and page limits. The limits aren't marketing — they're set where conversion time starts to grow faster than file size, and each tool page states its own.

Your file's lifecycle

• 1.Your file is uploaded over SSL and stored in a temporary directory.
• 2.The conversion job runs against it with one of the engines above.
• 3.The uploaded original is deleted the moment the job finishes — success or failure.
• 4.The converted result stays available just long enough for you to download it, then it's cleaned up automatically too.

Nobody reads your files, and there's no archive of past conversions. The full policy is on the privacy page.