SoloPDF vs Calcium Text Calculator

SoloPDF is a clean, fast, fully local PDF reader — no ads, no account, nothing ever uploaded. • Reading: multiple tabs, outline, page thumbnails, full-text search, fit-width/fit-page zoom. Huge files open instantly thanks to on-demand loading. • Highlights become notes: highlight any text and the annotation is saved as a Markdown notes file (.annotations.md) right next to the PDF — open, edit, and version it with any editor (including our SoloMD). solopdf:// links inside the notes jump straight back to the highlighted passage. • Forms: fill AcroForm PDFs (text fields, checkboxes, dropdowns) and save the result. • Export to Markdown: turn a whole PDF into a Markdown document, outline headings included. • Dark mode with smart page inversion for comfortable night reading. • Interface in English, 简体中文, 繁體中文, and 日本語. Everything runs on your device. No network calls, no data collection.

Calcium is a text editor that updates math results as you type. Use `=>` to compute expressions. It supports all kinds of units. Best of all, it's free and open source!