Why maths loses its shape in plain text
Every superscript, fraction bar and integral sign in a piece of maths is carried by the layout rather than by the characters. Copy an equation out of a PDF, a chat message or a spreadsheet cell and the layout is exactly what gets dropped: a raised two becomes an ordinary digit, a fraction bar becomes a slash, and a summation sign becomes the word sum or nothing at all.
x2 + y2 = r2 → x^2 + y^2 = r^2
This tool reads that flattened text back into LaTeX, and renders the result with KaTeX so you can check it. Both halves happen in your browser — the text is never sent anywhere — and the LaTeX stays editable, because a converter that guesses has to let you correct it.
Reading an equation from a picture
Switch the input to Image and you can choose a file or drop one onto the panel. You do not have to switch first to paste: pressing Ctrl+V with a picture on the clipboard moves you to the Image tab and loads it, wherever you were — pasting an image is unambiguous about what you want, so the tool follows rather than asking. Pasting ordinary text is untouched and still goes into the box you are typing in. PNG, JPEG and WebP, up to five megabytes. A picture with several equations in it comes back as several numbered tabs, each one editable and previewable on its own.
This is the one thing in this tool that leaves your browser, and the panel says so above the controls rather than down here. The image is sent to this site's server, forwarded to a recognition model, used once and discarded — nothing is stored, and no credential ever reaches the page. A challenge sits in front of the request, because a model call costs this deployment money and an open one would be drained by a script within a day.
The result is a transcription, not a reading of your intent. Every equation it produces is marked as read from a picture, for the same reason the text converter marks its guesses: the preview is the check. Crop to the equation and send the original rather than a thumbnail — the recognizer refuses anything under a kilobyte, because a file that small is a truncated download rather than a picture of maths.
What the converter understands
The vocabulary is deliberately small and completely documented, so you can see what it will and will not read rather than guessing at a guesser.
| Write | What it does |
|---|---|
| x2 · x^2 · x² | Digits straight after a single letter are read as a power. A space stops it, so a letter and a spaced digit stay two separate things. |
| a/b | The numerator is the whole term before the slash, back to the nearest plus, minus, equals or comma. |
| sqrt(x) · cbrt(8) · abs(x) | Roots take a bracketed argument, or the next single thing when there are no brackets. |
| sum i=1 to n of … | Also product, integral, oint, union and intersection. The words from, to and of are all optional — but without of, a limit is one thing. |
| lim as x->0 of … | A limit takes a lower bound only, which is what TeX does with it too. |
| alpha · Omega · pi | Every Greek name, lower and upper. A capital TeX has no command for becomes its Latin letter, which is what a TeX author writes by hand. |
| <= · >= · != · -> · +- · * | The ASCII spellings of the relations, and the pasted symbols for them as well. |
| sin · cos · log · ln · exp | Set upright, so a function name does not read as a run of variables multiplied together. |
| dx · dy · dt | Read as a differential only on a line that has an integral on it. Anywhere else it is two ordinary letters. |
| \frac{a}{b} | LaTeX you already have passes through untouched, so you can paste half of it and finish here. |
Anything the table does not cover is passed through exactly as it was typed. That is deliberate: a converter that rewrites what it does not understand produces LaTeX that looks finished and is not.
Pasting LaTeX an assistant gave you
Ask a chatbot for an equation and it answers with the delimiters still attached — because that is how maths is written inside a document, not how a renderer takes it. All five shapes are unwrapped on the way in, so you can paste the reply exactly as it came.
Single dollars and double dollars, the TeX pairs, and a fenced code block are all recognised. Anything already clean is left alone, so LaTeX you wrote yourself passes straight through.
The wrapper is read as well as removed, because it says something the equation itself cannot: double dollars and the square-bracket pair mean the author wanted a display block, single dollars and the round-bracket pair mean inline. The display switch is set from it. Text with no delimiters says nothing about display, so the switch is left where you put it.
A block spread over several lines — the delimiters on their own lines with the equation between them — is kept as one equation rather than being read as three, two of which would be punctuation.
Where it guesses, what it offers, and how you settle it
Three of those rules resolve a genuine ambiguity in the text. The tool takes a reading, tells you it did, and — where more than one answer is defensible — hands you the alternatives already converted, each with its own preview. You choose by looking rather than by rewriting.
Digits after a letter. x2 is a power, H2O is a subscript, and h264 is a name. Nothing whatever in those characters separates them, so the tool stops pretending it can tell: it reads them as powers by default and offers the subscript and the as-typed readings beside it.
How far a fraction reaches. n(n+1)(2n+1)/6 most likely means the whole product over six, so that is the default — with the narrower reading, where only the last factor sits over the six, offered next to it.
An unclosed bracket is closed for you rather than refused, because a half-typed line should still show you something. There is nothing to choose here: the other reading is not an equation.
The surest fix is to say what you mean in the input, and the tool will not guess at what you have already stated. Write H_2O for a subscript, a^2 for a superscript, and brackets around a numerator you want kept whole. An input that settles the question produces one reading and no picker at all.
The preview is the check, and it is why the preview is not optional. Read the rendered equation rather than the source: LaTeX that parses is not the same as LaTeX that says what you meant.
Taking it away
Four formats, from one Copy button with a format picker beside it.
| Format | Gives you | Reach for it when |
|---|---|---|
| LaTeX | \frac{a}{b} | You are writing LaTeX, or pasting into anything that already expects it. |
| Markdown | $\frac{a}{b}$ | The equation belongs in the run of a sentence, in a Markdown document. |
| Markdown block | $$
\frac{a}{b}
$$ | The equation is a display block. The fences go on their own lines, because two dollars on one line are read differently by different parsers. |
| MathML | <math><mfrac><mi>a</mi><mi>b</mi></mfrac></math> | You need markup a browser or a screen reader reads natively, with no library. It is produced by KaTeX, so it needs source KaTeX can parse. |
The download is a .tex file with one display block per equation, and the line you typed written above each one as a comment — so the file still says what was generated from what, a week later.
What people use it for
Getting an equation out of a PDF or a slide and into a document. The paste has lost its superscripts and its fraction bars; this puts them back and shows you the result before you commit it to a paper.
Writing maths in a notes app, a README or a chat message without remembering LaTeX. Type it the way you would say it, press Convert, copy the Markdown.
Checking LaTeX you already have. Paste it in, and the preview tells you whether it renders and what it renders as — which is a great deal faster than a build.
Frequently asked questions
x2 and wrong for H2O or a name like h264. Look under the source box: the other readings are already converted and previewed, so switching to the subscript or the as-typed version is one press. To skip the question entirely, write it outright in the input — H_2O for a subscript, a^2 for a superscript — and nothing is guessed at.