New · Information Erasure Observatory

What the record lost — sealed so it can't be lost again

Most censorship trackers answer one question: is this reachable right now? Palimpsest answers a different one. It measures what was removed or rewritten — across three layers of the record — and hash-chains every reading at the moment we take it, so our own account of the erasure can never be quietly edited afterward. We observe from outside the wall; we put no one inside it at risk.

Loading the live reading…

How this differs from an access index

An access observatory measures…	whether a site, app or tool is reachable at this instant.
The Erasure Observatory measures…	what existed and is now gone or altered — a page that got shorter, an encyclopedia entry rewritten to the state line, an answer a model used to give and now refuses.
Anyone can publish a live number…	so the number alone proves nothing. The hard part is proving you did not edit your own history after the fact.
Our answer…	every reading is sealed into a public, append-only, tamper-evident ledger at capture time. Recompute the chain yourself — a single altered or dropped past reading fails to verify.

Method: vantage-insensitive. Each layer ingests already-public data (OONI's aggregated measurements, the open encyclopedic record, a panel of state-aligned models queried from outside the wall) and never asks any person inside China to act. Judgement is lexical and auditable from the text. The composite is the mean of the layers that reported; absent layers are shown as absent, never zero-filled. Grounded in the trusted-public-archive literature (ARCHANGEL, arXiv:1804.08342) and the LLM-censorship measurement work (arXiv:2505.17441, arXiv:2506.12349). Not affiliated with OONI or Censored Planet; we ingest their open data with thanks. · raw JSON · the ledger