Overlay

Turn a Google Doc or Sheet into a reusable smart template — highlight text, create a variable, edit it once, sync everywhere.

Overlay turns a Google Doc or Google Sheet you already have into a reusable template — without leaving the editor, rewriting your file, or learning a new tool. Say you send the same proposal to different clients. The client name appears eleven times, the price appears four times, the date twice. Today you find-and-replace each one and hope you didn't miss any. With Overlay you turn each into a variable once, then change it in one place — and every occurrence updates in the real document, instantly. HOW IT WORKS 1. Select text (or a cell in Sheets) — a client name, a date, a price — and copy it with Cmd/Ctrl+C 2. Click "Create Variable" in the sidebar and give it a name 3. Every occurrence gets a subtle colour tint, so you can see exactly what that variable controls 4. Edit the value in the sidebar — every occurrence updates in the document, live WHY NOT JUST FIND AND REPLACE? Because it is easy to miss an occurrence, easy to replace one you didn't mean to, and there is no record of which values are the ones that change next time. Overlay keeps that structure with the file, so the document stays reusable instead of being rebuilt by hand every time. WHY NOT A TEMPLATE TOOL? Most document automation tools ask you to migrate your files into their system, or to rewrite them with {{placeholder}} syntax that makes the document unreadable to everyone else. Overlay works on your files exactly as they are today. Nothing to import, nothing to rewrite, and the document still reads normally to anyone you send it to. LOOKING FOR MAIL MERGE? Not quite the same thing, and worth being clear about. Mail merge generates many documents from a spreadsheet of rows. Overlay makes one document reusable — you keep the same file and swap its values whenever you need it again. If you reuse one proposal, contract, or pricing sheet over and over, Overlay is the better fit. If you need to generate 200 personalised letters in a single run, a mail merge tool is. BUILT FOR Sales teams sending proposals. Consultants and agencies reusing SOWs and pricing sheets. HR generating offer letters. Legal updating NDAs. Finance maintaining recurring models and trackers. Anyone who edits the same document or spreadsheet structure over and over. WHAT'S INCLUDED • Works in both Google Docs and Google Sheets • Unlimited variables and documents — no caps • Live sync: one edit updates every occurrence in the real file • Colour-coded highlighting so you can see every variable at a glance • Google Sheets: bind a variable to one cell, every matching cell in a sheet, or every matching cell across the entire spreadsheet — your choice, and changeable later • Multi-tab Google Docs fully supported • Search and filter your variable list • Clean PDF and Word export — highlight colours are stripped from the downloaded file • Duplicate a document or spreadsheet and its variables come with it • Built-in undo for value edits and deletions • Free, with no account required YOUR DOCUMENTS STAY YOURS Overlay reads and edits only the Google Doc or Sheet you currently have open, and only while you are using it. Your document content is never sent to our servers — variables are stored locally in your browser. No account, no sign-up, and no tracking of your documents. Questions, bugs, or ideas: https://www.overlaylab.co/support