Local-first or hosted: two ways to build an AI summarizer
Some summarizers keep your notes on their servers, others keep them on your device. Two questions tell them apart: where is the text processed, and where are the results stored?
Allan Warsing
AI summarizers look alike from the outside. You paste a link or click a button, and a summary appears. Underneath, they make two choices that matter far more than the interface: where your text is processed, and where the results are stored.
Where the text is processed
Every AI summary is written by a language model running in someone's data center. The real question is whose account it runs under and who sits in the middle.
A hosted summarizer usually sends your text to its own server first, which then calls a model under the company's account. A BYOK tool like Reduz sends the text from your browser straight to the provider you chose, under your account. There is one fewer company handling your reading.
Where the results are stored
Hosted products tend to store your summaries on their servers and sync them through an account. That is convenient: your notes follow you to every device. It also means your reading history lives under someone else's retention policy.
Reduz stores summaries in your browser profile instead. They are private by default and readable offline, but they stay on that one browser. You keep them safe by exporting your history as JSON or a Markdown ZIP.
The honest trade-offs
- Sync: hosted wins. Local history does not follow you between devices.
- Fewer parties: local-first wins. Only your chosen provider sees the text.
- Billing: hosted is simpler with one subscription. BYOK means paying the provider directly, at its own prices.
- Durability: hosted keeps a copy for you. With local history, you are responsible for exports.
If you read on a phone, a work laptop, and a home computer and want one shared library, a synced service fits better. If you want to know exactly who sees your text, local-first is easier to reason about.
What to check in any tool
Read the privacy policy for three answers: whether your text passes through the company's servers, how long summaries are kept, and whether you can export everything in an open format. If the policy leaves one of them vague, ask support before you rely on the tool.