Number line & interval visualizer

Shade inequalities, unions, and intersections on a responsive number line while documenting every algebraic step for teaching, study guides, or quick checks.

Built-in parsers understand <, ≤, fractions, and compound statements with AND / OR. Export SVG or PNG for worksheets, print to PDF, and keep presets through shareable URLs.

Other languages: ja | en | es | zh-CN | nl-nl

Shade inequalities and interval notation instantly

Toggle between inequality parsing, a guided interval builder, and interval text input to cover every classroom workflow. The visualizer converts results into both interval and inequality notation and merges overlaps automatically.

Domain controls support negative infinity, fractions, and decimal steps, making it easy to prototype entrance exam questions, SAT-style practice, or lecture slides in seconds.

Number line configuration

Domain

Preview

Number line & interval visualizer (inequality shading)

Shade inequalities and unions, show steps, and export as SVG/PNG.

How it's calculated

    Classroom-friendly exports and keyboard shortcuts

    Press Enter to regenerate after editing any input, press Ctrl+S for CSV, Ctrl+L to copy the shareable URL, and Ctrl+P to open the print dialog. Share links preserve mode, domain, and interval settings for students.

    SVG downloads stay crisp for textbooks and slides, while PNG gives a quick screenshot for LMS uploads. CSV lists every shaded interval and the domain limits for fast documentation.

    Frequently asked questions

    How do I enter compound inequalities or mixed unions?

    Combine clauses with AND / OR (or the ∪ symbol) in the inequality tab. The solver handles each clause, flips signs when coefficients are negative, and merges overlaps into a clean union.

    What export options are available for the number line?

    Download SVG for crisp printouts, render a PNG screenshot, export CSV rows with endpoints, copy a shareable URL, or print to PDF directly from the browser.