Image to LaTeX, offline

You have an equation as a screenshot, in a slide, a scanned page or a PDF, and you want it as LaTeX. Most image-to-LaTeX tools upload the picture to a server. Here is how to do it entirely on your own computer, and what the alternatives are.

Updated 2026-10-05

The quick way

1. Snip the equation. Press Ctrl+Alt+T anywhere on screen and drag a box around it, or drop an image file on the CatchTeX window. If the equation is in a PDF, open the PDF in CatchTeX (Ctrl+O) instead: the symbols are then read from the file itself, which is exact.
2. Pick the style with the chips above the preview: \[ \], $$, equation, equation*, $ or \( \). Turn on (n) to keep the paper's equation number as \tag{n}.
3. Check the compiled preview next to the code, fix anything in the editor if needed.
4. Copy LaTeX (Ctrl+Shift+C) and paste it into Overleaf or your editor.

\begin{equation}
E = \int_0^{\infty} e^{-\alpha x}\,dx
\tag{3}
\end{equation}

What "offline" means here

The maths model (PP-FormulaNet-S, run with ONNX) and the text recognition (Tesseract) are part of the installer and run on your processor. No account, no internet connection and no Python installation are needed, and the image never leaves your computer. That matters for unpublished work, theses under embargo and documents under a non-disclosure agreement.

How good is it?

On our test set of 30 equations rendered as images, all 30 results compile and the LaTeX matches the original with 0.97 similarity on average. In practice: typical display equations come out right or need a small fix; very long multi-line derivations and unusual notation need more checking. The compiled preview makes mistakes easy to spot before you copy. Handwritten maths is not supported.

Other ways, compared

Tips

• Snip tightly around the equation, but include the number on the right if you want to keep it.
• A bigger image reads better: zoom in on a small equation before you snip it from the screen.
• For equations inside a PDF, open the PDF in CatchTeX rather than taking a screenshot: exact symbols beat recognition.
• Auto mode tells you when a snip looks like a table or text instead; click the suggested mode to re-read it.

Questions