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LaTeX to speech: turn an equation into spoken English.
Paste a LaTeX equation and get the words a lecturer would say for it. Use the result as alt text, in lecture notes, or to check how a formula will sound. It runs the speech engine that narrates books in Aethel Audio, in your browser.
Read aloud as
x equals the quantity negative b plus or minus the square root of the quantity b squared minus 4 a c, all over 2 a
Converted in your browser: nothing you type is uploaded. One equation at a time; the result is in English.
How to use it
- Paste or type a LaTeX equation in the box. Dollar signs and \[ \] around it are ignored.
- Read the spoken form that appears underneath; it updates as you type.
- Press Copy to use it as alt text, in lecture notes or in a script for narration.
What people use it for
- Alt text for equations. An image of an equation needs a text alternative that says the equation. The spoken form is that text. See how to write alt text for equations.
- Lecture notes and slides that will be read aloud. Put the words next to the formula for students who listen, or for your own recording.
- Checking how to say a formula. Before a talk, a viva or a video, see one clear way to read each equation.
- Describing maths in plain text. In email, chat and forums where LaTeX does not render.
How LaTeX is read aloud
The converter reads what an equation means, not the characters it is typed with. A few examples from each area of notation; the full reference explains the rules.
| LaTeX | Read aloud as |
|---|---|
| \frac{a}{b} | a over b |
| \frac{x + 1}{x - 1} | the quantity x plus 1, all over the quantity x minus 1 |
| x^2 | x squared |
| x^3 | x cubed |
| x^{n+1} | x to the power of n plus 1 |
| e^{-x} | e to the power negative x |
| LaTeX | Read aloud as |
|---|---|
| \sum_{i=1}^{n} x_i | the sum from i equals 1 to n of x sub i |
| \prod_{i=1}^{n} x_i | the product from i equals 1 to n of x sub i |
| \int_a^b f(x)\,dx | the integral from a to b of f of x, d x |
| \int x^2 \, dx | the integral of x squared d x |
| \oint_C \mathbf{F} \cdot d\mathbf{r} | the contour integral over C of F dot d r |
| \lim_{x \to \infty} f(x) | the limit as x goes to infinity of f of x |
| LaTeX | Read aloud as |
|---|---|
| \frac{dy}{dx} | the derivative of y with respect to x |
| \frac{\partial f}{\partial x} | the partial derivative of f with respect to x |
| f^{\prime}(x) | f prime of x |
| \dot{x} | x dot |
| \nabla f | the gradient of f |
| \nabla \cdot \mathbf{F} | the divergence of F |
| LaTeX | Read aloud as |
|---|---|
| \hat{y} | y hat |
| \bar{x} | x bar |
| \vec{v} | vector v |
| A^\top | A transpose |
| \mathbf{A}^{-1} | A inverse |
| \det(A) | the determinant of A |
| LaTeX | Read aloud as |
|---|---|
| x \in A | x in A |
| A \subseteq B | A is a subset of B |
| A \cup B | A union B |
| A \cap B | A intersection B |
| \forall x | for all x |
| \exists x | there exists x |
| LaTeX | Read aloud as |
|---|---|
| P(A \mid B) | P of A given B |
| \mathbb{E}[X] | the expected value of X |
| \operatorname{Var}(X) | the variance of X |
| x \sim \mathcal{N}(\mu, \sigma^2) | x is distributed as N of mu, sigma squared |
| \binom{n}{k} | n choose k |
| n! | n factorial |
What it does not do
- It cannot know what your notation means. A bar, a prime or a raised −1 is read by the usual convention, so check the result against the equation.
- It reads one equation, not a document. For a whole paper or textbook, Aethel Audio rebuilds every equation in the PDF and reads the text around it too.
- It does not define your own macros. Expand them, or replace them with standard commands, before pasting.
Questions
What does the converter do?
It turns a LaTeX equation into the English words a lecturer would say for it: \frac{a}{b} becomes “a over b”, x_i^2 becomes “x sub i squared”. It reads the structure of the equation, so fractions, powers, sums and integrals come out in a form a listener can follow.
Is it free? Do I need an account?
It is free and needs no account. The conversion runs in your browser, so the equation you type is not uploaded.
Can I use the result as alt text?
Yes, that is one of its main uses. Copy the spoken form, add a capital letter and a full stop, and check anything that depends on context, such as whether a bar means “given” or “absolute value”. See how to write alt text for equations.
Which LaTeX does it understand?
The maths in everyday use: fractions, roots, powers and subscripts, sums, products, integrals and limits, derivatives, vector calculus, matrices, sets, logic, probability and Greek letters. Custom macros and rarely used packages are read as written. The reference lists the spoken form of common commands.
Does it speak the equation aloud?
It gives you the words. To hear whole textbooks and papers read aloud with the equations spoken this way, use Aethel Audio itself: the equation demo plays recordings of well-known formulas, and the free trial reads your own PDF.
Does it work in other languages?
The converter writes English. In the app, a chapter can be translated into any of 17 languages and narrated in the translation.
Every equation in your reading, said like this.
Upload a textbook or paste an arXiv link and Aethel reads it aloud, equations included, highlighting each sentence. Free to start: five books and an hour of narration, no card needed.