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How Does Underleaf Work? Web App, Chrome Extension, and Credits Explained

15/06/2026

Ioannis Baroumas Ioannis Baroumas
Underleafhandwriting to LaTeXOverleafcomparisonworkflow

If you search how does Underleaf work, you are usually deciding whether to sign up before a deadline — and whether the workflow matches how you actually write (Overleaf tabs, phone photos of lecture notes, or batch PDF uploads).

Underleaf is an AI-powered academic writing platform built around LaTeX conversion and Overleaf integration. This guide explains the two ways to use it, what happens when you upload a page, how credits are consumed, and when the tool is a strong fit — based on Underleaf’s public FAQ and product pages.

Try StoicDocs free → if you want to compare full-page handwriting conversion on your own notes before committing to a subscription.

How does Underleaf work?

Underleaf operates in two connected modes that share the same credit pool:

  1. Underleaf web app (app.underleaf.ai) — a standalone workspace where you upload images or PDFs and run conversion and writing tools.
  2. Chrome extension — AI features embedded inside Overleaf, including inline image-to-LaTeX, citation helpers, and dark mode.

You create an account, pick a plan (free or paid), and each AI-powered action — conversions, AI edits, and similar features — draws from your monthly credit allowance. Credits reset each billing cycle; they do not roll over indefinitely.

The Underleaf web app workflow

The web app is where most users start. According to Underleaf’s FAQ, available tools include:

A typical session looks like this:

  1. Sign in at the web app and open the relevant converter (image, PDF, or handwriting).
  2. Upload your file — JPEG, PNG, or PDF depending on the tool.
  3. Underleaf’s AI processes the content and returns LaTeX source code you can copy.
  4. Paste the output into Overleaf, a local editor, or another toolchain.

Paid plans allow larger PDF batches: up to 10 pages per upload on Essentials and up to 20 on Pro, per their pricing page. The free tier includes access to conversion tools but only 10 credits per month.

For a detailed breakdown of plans and costs, see our Underleaf pricing explained guide.

The Chrome extension workflow (inside Overleaf)

If you already live in Overleaf, the extension is Underleaf’s differentiator. Install it in Chrome or another Chromium browser (Edge, Brave), log in with the same Underleaf account, and the toolbar appears inside your Overleaf project.

The extension adds:

Credits consumed in the extension share the same monthly pool as the web app. Snipping ten equations in Overleaf and uploading two PDF pages on the web both count against your allowance.

Underleaf states it does not store document content permanently and does not access your Overleaf login credentials — processing happens on content you explicitly submit. See their privacy policy for full details.

What uses a credit?

Underleaf’s FAQ is clear: each AI-powered action uses credits. That includes:

There is no published per-action credit cost on the public FAQ — you learn your burn rate by using the tool. Dense math pages with many nested expressions may consume more credits than simple text scans.

On the free plan, 10 credits per month is enough to test quality on a handful of pages, not to digitize a full semester. Most regular users upgrade once they hit the cap.

Underleaf for handwritten notes vs equation snippets

Underleaf markets heavily on handwritten lecture notes → LaTeX in seconds. The web app’s image and handwriting converters target full pages or photos of notebook spreads.

The Chrome extension, by contrast, excels at targeted snippets — one equation, one table, one diagram — while you edit in Overleaf. Many students combine both: batch-convert notebook pages in the web app, then fine-tune individual expressions via the extension.

If your workflow is equation-by-equation rather than full-page, Mathpix Snip is the more common choice. See our Mathpix Snip pricing explained post for how that workflow differs.

When Underleaf is a good fit

Choose Underleaf if:

Consider alternatives if:

For a side-by-side feature and pricing comparison, see Underleaf vs StoicDocs. Shopping more broadly? Browse Underleaf alternatives. If your pain point is Overleaf’s collaboration or compile limits rather than handwriting OCR, see Overleaf alternatives.

How StoicDocs fits the same problem differently

StoicDocs also converts handwritten notes to LaTeX and PDF, but the product is built as a document workspace rather than a converter-plus-extension bundle:

StoicDocs is not a drop-in replacement for Underleaf’s Overleaf Chrome extension. If you live inside Overleaf and love inline Snip-style tools, Underleaf’s extension ecosystem is hard to beat. StoicDocs fits researchers who want to convert, edit, organize, and optionally hand off hard formatting to a human.

Convert a sample page free at StoicDocs — no credit card required — and compare output on the same handwritten page before buying an annual Underleaf plan.

Ready to compare? Try StoicDocs free. For thesis or dissertation formatting, request a quote at /thesis-help.

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