An open-source spreadsheet for data that doesn’t fit in a spreadsheet. Hundreds of millions of rows, real Excel formulas, SQL when you want it. Runs on your machine; your data never leaves it.https://alephgrid.dev/enhttps://alephgrid.dev/blog/introducing-alephgrid/https://alephgrid.dev/blog/introducing-alephgrid/An open-source spreadsheet for data that doesn't fit in a spreadsheet — hundreds of millions of rows, real Excel formulas, SQL when you want it, running entirely on your own machine. Sun, 01 Nov 2026 00:00:00 GMT<p>Spreadsheets are the most successful data tool ever made, and they stop working the moment your data gets big. Databases handle the big data and stop working the moment you want to <em>touch</em> it — format a column, write <code dir="auto">=SUMIFS(...)</code>, drag a fill handle.</p> <p>Alephgrid is our attempt to remove that trade-off. It’s an open-source (Apache-2.0) spreadsheet that opens CSV and Parquet files with hundreds of millions of rows, keeps them scrollable and editable in your browser, and puts an ordinary, Excel-compatible spreadsheet right next to them — with formulas that can read the big tables directly.</p> <div><h2 id="how-it-works">How it works</h2></div> <p>One Rust binary with the UI embedded. Every workbook is a DuckDB file on your machine. Opening a workbook reads nothing into memory: the grid requests only the rows on screen, sorts build a permutation instead of a copy, and calculated columns compute only what you look at.</p> <p>Sheets run on <a href="https://github.com/ironcalc/IronCalc">IronCalc</a>, an Excel-compatible engine, so <code dir="auto">XLOOKUP</code>, <code dir="auto">SUMIFS</code>, dynamic arrays, <code dir="auto">LET</code> and <code dir="auto">LAMBDA</code> behave the way you expect. And a sheet formula like <code dir="auto">=SUMIFS(orders[amount], orders[region], A2)</code> compiles to one query over the whole table — not one lookup per row.</p> <div><h2 id="whats-in-the-first-release">What’s in the first release</h2></div> <p>v0.1.0 is being prepared now. It ships sheets with formatting, charts, comments and XLSX round-trip; big tables with sort, filters, calculated columns and the Analyze pane; reusable functions in sheet-formula, SQL or sandboxed Python form; an optional SQL workspace; teams with spaces, roles, SSO, quotas, audit and backups; and read-only <a href="https://github.com/alephgrid/alephgrid/blob/main/docs/MCP.md">MCP access</a> so AI agents can query a workbook with a content-hashed receipt for every result.</p> <p>There are no seats, tiers or paywalls. Export, sign-in, teams — everything is free.</p> <div><h2 id="try-it-today">Try it today</h2></div> <p>Until binaries ship, you can <a href="../../docs/getting-started/">build from source</a> in a few minutes (plus one DuckDB compile):</p> <div><figure><figcaption><span></span></figcaption><pre><code><div><div><span>git</span><span> </span><span>clone</span><span> </span><span>https://github.com/alephgrid/alephgrid</span><span> &#x26;&#x26; </span><span>cd</span><span> </span><span>alephgrid</span></div></div><div><div><span>(</span><span>cd</span><span> </span><span>web</span><span> &#x26;&#x26; </span><span>npm</span><span> </span><span>install</span><span> &#x26;&#x26; </span><span>npm</span><span> </span><span>run</span><span> </span><span>build</span><span>)</span></div></div><div><div><span>cargo</span><span> </span><span>build</span><span> </span><span>--release</span></div></div><div><div><span>./target/release/alephgrid</span><span> </span><span>--demo-rows</span><span> </span><span>10000000</span></div></div></code></pre><div><div aria-live="polite"></div></div></figure></div> <p>Follow the <a href="../../releases/">releases page</a> for v0.1.0, and if something breaks, an issue with a reproducible file is the most valuable thing you can send us.</p>