This website allows you to convert LaTeX math into MathML (or, more specifically, MathML Core), which is then rendered by your browser. For example, try this input:
\int \mathcal{D}\!x =
\lim_{N \to \infty}
\left( \frac{m}{2\pi i \hbar \Delta t} \right)^\frac{N}{2}
\int\!\cdots\!\int \prod_{i=1}^{N-1} dx_iRecent versions of all the major browsers support MathML Core, so you should be able to see the rendered math.
The conversion runs entirely in your browser, using WebAssembly and a tiny bit of JavaScript. Your LaTeX math is never sent to a server. The compiled WebAssembly is under 100kB; less than many images on the web. If you don’t have the font Latin Modern Math installed on your system, then this also needs to be downloaded. The font file is 379kB.
Not all features of LaTeX math are supported. Some of them simply because they haven’t been implemented yet; others because they are very difficult to translate into MathML.
If you need multiline equations, you can use the
environments \begin{aligned},
\begin{align}, or \begin{align*}.
For example:
\begin{aligned}
x &= 1 \\
y + z &= 2
\end{aligned}