Browser Storage Comparison: sql.js vs IndexedDB vs localStorage

Originally published at recca0120.github.io Browser-side storage has more options than most developers expect. localStorage is the simplest but the most limited. IndexedDB is powerful but its API is notoriously verbose. sql.js gives you a full SQL engine running entirely in the browser. Each has its place, and picking the wrong one early costs you later. This article compares the three across capacity, API style, query capability, and performance, then wraps up with a decision framework you can use before you write a single line of storage code. Overview of Each Option localStorage / sessionStorage The veteran of browser storage. Key-value string storage with a synchronous API and virtually no learning curve: // Store data localStorage . setItem ( ' user ' , JSON . stringify ({ name : ' Alice ' })) // Retrieve data const user = JSON . parse ( localStorage . getItem ( ' user ' )) sessionStorage shares the same API but clears when the tab is closed. The limitations are hard to ignore: st