How São Paulo's Digital Archives Fell Into the Duplicate Image Trap — and What the City Is Doing About It

São Paulo's municipal government is sitting on a problem that has been quietly compounding since at least 2004: public digital archives — from urban planning records to cultural heritage photo libraries — are bloated with duplicate images, some files replicated dozens of times across incompatible systems managed by different secretariats. The issue, long treated as a low-priority IT concern, has become harder to ignore as the city's storage costs climb and federally funded transparency initiatives demand cleaner, interoperable data.

The timing matters. Brazil's Lei de Acesso à Informação, in force since 2012, obliges public bodies to make digital records genuinely searchable and retrievable. Fourteen years on, several of São Paulo's secretariats are still wrestling with archives where the same photograph of, say, a flooded underpass on Avenida dos Bandeirantes appears under three different file names, in two different resolution standards, stored on servers that do not talk to each other. When journalists or researchers submit freedom-of-information requests, staff must manually sift through the redundancy — a process that delays responses and, in some documented cases, results in contradictory records being released simultaneously.

How the Duplication Accumulated

The roots of the problem stretch back to the mid-2000s, when individual municipal bodies digitised their own paper archives without a shared protocol. The São Paulo City Council's Arquivo Histórico Municipal, based on Rua Dona Antônia de Queirós in Higienópolis, digitised thousands of images independently from the Secretaria Municipal de Cultura, which ran its own parallel project. Neither effort was synchronised with the urban planning records held by the Secretaria de Urbanismo e Licenciamento, whose offices process permit documentation for the city's roughly 11 million residents in the urban core alone.

Each wave of technology procurement made things worse. When administrations changed — and São Paulo has cycled through several mayors since those early digitisation drives — incoming teams often commissioned new scanning and cataloguing contracts rather than inheriting and extending existing ones. Contractors delivered files in whatever format their own software generated. The result, by the early 2020s, was a patchwork: TIFF files sitting alongside low-resolution JPEGs of the same document, metadata fields filled in inconsistently or left blank, and no single authority responsible for deduplication across the whole estate.

Storage is not free. Municipal IT infrastructure in large Brazilian cities typically runs on a hybrid of legacy on-premise servers and cloud contracts negotiated at state level. While the precise costs inside São Paulo's current contracts are not publicly itemised in the city's 2026 budget portal as of this writing, the federal government's own Tribunal de Contas da União flagged redundant digital storage as a source of unnecessary expenditure across multiple municipal audits published between 2021 and 2024 — findings that apply to large metropolitan administrations across Brazil, including the capital of São Paulo state.

The Push Toward a Fix

Pressure for a solution has come from two directions simultaneously. From above, the federal government's Rede Nacional de Dados em Saúde and the broader push toward interoperability under the Estratégia de Governo Digital, launched in 2020 and updated in 2022, have created expectations that municipal archives will meet minimum data-quality standards. From below, civil society organisations based in the city — including groups working out of the Centro Cultural São Paulo on Rua Vergueiro in Paraíso — have used open-data audits to expose inconsistencies in the public record.

The current Nunes administration has indicated, in procurement notices published on the Portal da Transparência da Prefeitura de São Paulo earlier this year, that it intends to consolidate several secretariat archives under a unified document management platform. The process involves algorithmic deduplication — software that compares file hashes to identify identical or near-identical images — followed by human review for cases where content is similar but not identical, such as sequential photographs from the same urban inspection visit.

For residents and organisations that rely on public records — from architects pulling historical maps for renovation permits in Pinheiros to historians documenting the transformation of the old industrial belt along the Tamanduateí river — the practical upshot is straightforward: the city's digital holdings will become more reliable, and FOI responses faster, once the clean-up is complete. Municipal officials have not yet published a firm completion date for the consolidation project. For now, anyone navigating the archives should cross-reference multiple platforms and assume that the first result returned is not necessarily the only, or the authoritative, version of a given file.