Copenhagen's Digital Archives Are Riddled With Duplicate Images — And the Numbers Tell a Damning Story

Copenhagen's municipal digital infrastructure is carrying a hidden weight. An internal review of image assets held across city departments — including those managed by Københavns Kommune's communications directorate and the shared media library used by Teknik- og Miljøforvaltningen — has found that duplicate image files account for a significant share of stored data, driving up hosting costs and creating confusion for staff who rely on those systems daily.

The problem is not unique to Copenhagen, but the scale here has surprised administrators who began the audit process in late 2025. Across the city's primary asset management platforms, preliminary counts suggest that between 30 and 40 percent of stored image files are functionally redundant — same photograph, different filename, uploaded separately by different departments or at different times. That figure aligns with patterns documented by digital asset management consultancies across Scandinavian municipalities in recent years, though Copenhagen has not yet published a final official number.

What Duplication Actually Costs

Storage is cheap in isolation. A single duplicate image costs fractions of an øre to keep. Multiply that across tens of thousands of files and the arithmetic changes. City IT budgets that cover cloud and on-premise storage for administrative assets have grown steadily. Rådhuset's own budget documents from the 2025-2026 fiscal cycle show digital infrastructure spending rising by roughly 12 percent year-on-year across administrative units, though duplication cleanup was not itemised as a separate line.

The drag is not purely financial. Staff at Ørestad's district administration office and at the urban planning unit based near Islands Brygge have described — in general terms, in public-facing process documents — spending significant time hunting through multiple versions of the same image to find the highest-resolution or most recently approved file. The city's official photo library, which feeds everything from Kvarterplan neighbourhood plans to press materials for events at Amager Strandpark, relies on clean metadata and unique file identifiers. Duplicates break both.

The problem compounds itself. Each time a department uploads an image without checking whether it already exists in the system, the duplicate count grows. A photograph of Nørreport Station taken during a 2023 accessibility renovation, for example, reportedly exists in at least four separate folders under different naming conventions, according to process notes from a January 2026 working group on digital asset standardisation.

The Push Toward Systematic Replacement

The practical fix is unglamorous: a structured duplicate-image-replacement programme that uses hash-matching software to identify identical or near-identical files, consolidates them into a single master record, and then redirects all existing links to that master. Several European city administrations, including Amsterdam's gemeentearchief and Stockholm's stadsarkivet, have run comparable cleanups. Amsterdam's 2023 effort reportedly cut its active image library by 28 percent in file count while reducing storage overhead.

Københavns Stadsarkiv, the city's official archive based on Stærekassen near Rådhuspladsen, has been in discussions with the kommune's IT department about piloting a similar approach. A phased rollout, beginning with the highest-traffic image collections — those tied to building permit documentation and public communications — is under consideration for the second half of 2026.

For residents and journalists who regularly pull images from the city's public-facing media portal, a cleaner library would mean faster search results and fewer instances of pulling an outdated or low-resolution file by mistake. For the city's roughly 45,000 employees who interact with internal document systems in some capacity, the change would reduce friction in a mundane but persistent daily irritant.

The Kommune has not set a public deadline for completing the review. Anyone who regularly uses the city's digital asset tools and notices persistent duplication problems can flag them through the standard IT support portal managed by Koncern IT, which handles system-level feedback across Copenhagen's administrative units. Getting those reports in before the pilot phase begins may shape which collections get cleaned up first.