What it does
A Feynman diagram is a picture of a particle interaction: straight lines with arrows for electrons, quarks and other fermions, wavy lines for photons and W or Z bosons, curly lines for gluons and dashed lines for the Higgs and other scalars. This page draws one from a short text description, so you can change it quickly and get the same result every time.
You get the drawing on the page, an SVG (vector, for posters, slides and papers), a PNG at four times screen resolution, and TikZ-Feynman code to paste into a LaTeX document.
How to use it
- Start from an example or clear the box.
- Place each vertex on its own line:
name x y, with x to the right and y upwards (any units; 1 unit is 60 pixels by default). Adddot,blob,crossornoneto choose the mark; by default, vertices where three or more lines meet get a dot. - Join vertices with lines:
from to type label. The types are fermion, antifermion (arrow reversed), photon, gluon, W (wavy with an arrow), Z (wavy), higgs or scalar (dashed), ghost (dotted), plain and double. - Extras on a line:
bend=40curves it to the left by 40° (negative to the right; two bent lines between the same vertices make a loop),rightmoves the label to the other side, andp=kadds a momentum arrow labelled k. - Labels use a simple notation: Greek names (gamma, mu, nu, tau, pi, …), a trailing sign or zero as a superscript (
e-,mu+,pi0),^and_for super- and subscripts (W^+,nu_mu), and~for a bar (~nu_eis the electron antineutrino). - Choose the size, line width and label size, then download.
Worked example
The default example is electron-positron annihilation into a muon pair. Six vertices: the incoming e⁻ at (0, 2) and e⁺ at (0, 0), the two interaction points v1 at (1.5, 1) and v2 at (3.5, 1), and the outgoing μ⁻ and μ⁺ at (5, 2) and (5, 0). The photon line v1 v2 photon gamma p=q is drawn as a wave with the label γ and a momentum arrow q. The positron is written v1 i2 fermion e+, an arrow pointing back in time, as is usual for antiparticles. The page draws it with dots at v1 and v2, and the TikZ code starts \vertex (i1) at (0, 2); and contains (v1) -- [photon, edge label=\(\gamma\), momentum'=\(q\)] (v2).
Tips
- Keep vertices on a simple grid (whole or half units) and the drawing will look tidy.
- For a loop, join two vertices with two lines bent opposite ways, or one straight and one bent (see the electron self-energy example).
- The TikZ code needs
\usepackage{tikz-feynman}in your preamble. Because every vertex has a position, it compiles with ordinary pdfLaTeX.
FAQ
Does it check that the diagram is physically allowed? No. It draws what you describe; conservation of charge, lepton number and so on is up to you.
Can I change the drawing afterwards? Yes: the SVG is plain vector paths and text that any vector editor can open.
Is anything uploaded? No. The drawing, the files and the code are all made in your browser.
Where the numbers come from
- Line styles and LaTeX output follow the tikz-feynman package conventions: Ellis, J. P. (2017), TikZ-Feynman: Feynman diagrams with TikZ, Computer Physics Communications 210, 103 to 123 (style names only; no code copied).
- Example diagrams are standard textbook processes (QED scattering, Compton scattering, beta and muon decay, gluon fusion), drawn with our own coordinates.
- Geometry checked against the circle through the end points with the TikZ 'bend left' exit angle, in tests written for this page.
Standard scientific values, such as constants, atomic weights and melting points, are facts found in every textbook; we name where ours were checked. If you are an author or publisher and want a value, a credit or a table changed or removed, tell us and we will act quickly.
Last updated 2026-11-09.