Web platform

IndexedDB

IndexedDB is an asynchronous transactional database for structured browser data. It supports keys, indexes, and large records.

Ask the Web platform assistant 1 min read · Updated September 9, 2026

What it is

IndexedDB is an asynchronous transactional database for structured browser data. It supports keys, indexes, and large records.

Why it matters

Use it for durable local records, not as a synchronous global variable. Storage may be restricted or evicted.

Example

A chatbot stores public knowledge embeddings keyed by the model and knowledge-content hash, avoiding repeated encoding on later visits.

Technical detail

Transactions commit asynchronously. Resolve a write only on transaction completion, and handle aborts and version changes.

When to use it

Treat cache failure as recoverable, bound storage growth, and provide clear controls for any personal data you persist.

Go deeper

Sources

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Assembled from the ReLU.chat curated knowledge base. These explanations are concise on purpose; check the sources for anything important.