Chalkline
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Features

A drawing board with a maths engine inside.

Every tool below ships in the free download. Nothing is locked behind an account.

01 · Writing

The basics, done properly

An infinite board with multi-page slides, built for a finger, a stylus or a mouse.

  • Marker, highlighter, eraser, shapes, text and images
  • Smart brush: straightens lines and snaps circles and triangles
  • Presentation mode with a curtain and a spotlight
  • Export a lesson to PDF or PNG
smart brush
roughsnapped

02 · Graphs

Functions, derivatives, integrals

A coordinate plane that responds to your hands.

  • Unlimited functions with sliders for every coefficient
  • Derivatives and antiderivatives drawn alongside
  • Definite integrals: shaded area, movable limits, volume of revolution, arc length
  • Full analysis: domain, roots, extrema, inflection, asymptotes
  • Read values straight off the graph; trig circle; split screen
graph panel
b a f(x) = x² tangent at x = 2 ∫₀³ x² dx = 9

03 · Solids

3D geometry you can cut open

The thing a chalkboard can never do well.

  • 19 solids: prisms, pyramids, cones, cylinders, spheres and more
  • Mark points on edges and faces; cut by three points or horizontally
  • True-size section view
  • Area, perimeter, angles and the volumes of both parts
  • 3D brush for annotating the figure
solids panel
PQR section PQRequilateral triangle S = √3·a² / 8 corner piece = a³/24

04 · Solver & sketch

From handwriting to exact answers

Write in a frame on the board, as you would on paper.

  • Expressions, equations, inequalities and systems solved step by step
  • Handwriting recognition with per-teacher calibration
  • Sketch a rough curve or solid and convert it to an exact graph or figure
solver
2x + 3 = 11 recognisedas typed maths 2x + 3 = 11given 2x = 11 − 3move 3 across 2x = 8 x = 8 ÷ 2divide by 2 x = 4

05 · AI assistant (optional)

Ask the board to do things

Two modes. Rules works offline and understands ready-made English commands. Online understands free-form requests and can build graphs, figures, drawings and sections for you.

  • Off until you turn it on
  • Destructive actions always ask first
  • Bring your own OpenRouter key, or use a school server

Read how it is kept safe →

assistant

you  plot sin x and cos x from 0 to 2π

chalkline  Added 2 functions to the graph panel.

you  clear the board

Clear this page? This cannot be undone.  [Cancel] [Clear]

Reliability

Built so a lesson is never lost

  • Atomic autosave: write to a temp file, flush, then rename — a power cut cannot leave half a board
  • Rolling backups; a damaged board falls back to the newest valid copy
  • Deleted boards go to a trash folder, not into the void
  • A visible save status, automatic retries, and a warning if the last state could not be written
  • Strict Content-Security-Policy and a sandboxed renderer
  • 120+ automated tests plus an end-to-end smoke test of the real app

See it on your own board.

Download the free installer, or the portable build for a USB stick.

Download Chalkline