How to read this network list

What earns a place

A provider must have a documented dark fiber or optical wavelength offer and at least three sourced service or network fields beyond its name, website and summary. The dataset covers selected operators in North America, Europe, Asia-Pacific, Latin America and Africa. The offer field separates dark fiber from wavelength transport. The list is selective: 51 operators that publish enough to compare.

Where the facts come from

Operator product pages, network maps, technical sheets and official announcements come first. Uniti’s wider group footprint comes from its Q3 2026 Form 10-Q. Network sizes, SLAs and IRU terms are reported as each operator states them. The source list below contains every document used in the records.

Route length, fiber length and network scope

Route miles and route kilometers measure the path length. Fiber miles count individual strands along a path. Network kilometers, duct kilometers and unique trench length retain the source’s wording in the scope note. Numeric route fields are filled only when the source names that measure. We keep the original unit and never convert kilometers to miles.

Where a source says “more than” or adds a plus sign, the numeric cell stores the stated threshold and the adjacent scope note preserves the qualifier. We do not sum or rank network sizes, because footprints overlap and measure different things.

For example, Lumen’s route figure describes its low-loss next-generation subset. Uniti’s figure covers the combined company group. BIG Fiber’s figure covers the Bay Area. Their different scopes are part of the data.

Data-center access has several meanings

On-net means the source describes a network connection to the facility. Connected, serviceable, near-net, partner locations and colocation sites describe different access conditions. The DC scope field preserves that distinction and names regional subsets.

Geography and reach

Service region describes the documented offer, rather than headquarters or every destination reachable through partners. Global denotes a cross-region offer. Regional shortlists also include cross-region records where cited coverage supports them; counts overlap and are not summed. We normalize explicitly described metro/local and intercity/backbone services into the reach categories. MOX’s dark-fiber-channel products are kept separate from physical dark fiber corridors.

Missing values and conflicting pages

An empty cell means the operator does not publish a comparable figure, or its own pages disagree. FirstLight’s mileage stays empty because current pages disagree. Zayo’s route scope retains the date and geography of the latest announcement used for that field.

Dates and ownership changes

The access date is when the cited material was checked, not when the operator measured the network. Reporting periods and scope dates stay in the record where available. Zayo represents the acquired Crown Castle Fiber Solutions business, Segra represents Unite Private Networks, Bluebird represents its acquired Everstream assets, and Uniti represents the combined Windstream group. EXA represents the former GTT infrastructure division; Colt represents the former Lumen EMEA dark fibre estate. Provider records link to their current commercial identity.

Builds and AI projects

The build field carries each announcement date and stage: development, construction or live. Planned mileage stays out of the operating route columns. The AI and hyperscaler shortlist needs a specific project, partner or AI hosting build in the operator’s own documents, such as Zayo’s NVIDIA routes or Uniti’s hyperscaler IRU.

Comparisons and related providers

The table starts alphabetically. You can sort, search, filter and select providers to compare. Related links match on region, offer and reach, then name.

Quotes and corrections

Dark fiber is priced per route, so we publish terms rather than list prices. Email hello@darkfiberlist.com for introductions or a correction with a public source. Paid placements are labelled and keep their source facts independent of sponsorship.

Reuse

Our compilation and original copy are available under CC BY 4.0, with attribution to Dark Fiber List and a link to the relevant page. Source documents, provider trademarks and third-party materials retain their own rights. Download the CSV or JSON with field-level source mappings.