Custom Software Development Agencies in Illinois

32 custom software development agencies are listed in Illinois, United States. 4 have been assessed on the Agency List Score as of September 2026; the highest-ranked is Intersog at 78.1.

Ranked · 4 assessed

Ordered by Agency List Score
#1 of 4 assessed
Intersog
78
Verified

Custom software and AI solutions for diverse industries

Application DevelopmentData Engineering Pipelines
#2 of 4 assessed
Swip Systems
73
Verified

Custom software and mobile app development for diverse industries

Application Development
#3 of 4 assessed
TurnkeyTown
73
Verified

Blockchain and NFT development with Web3 and Metaverse solutions

Application DevelopmentData Engineering PipelinesDevSecOps Enablement
#4 of 4 assessed
Codeventures
53
Verified

Web and development services for inbound lead capture and search visibility

Mobile App Testing

Also in Illinois · 28 not yet assessed

Listed agencies queued for assessment. Alphabetical.

About this ranking

What this page ranks

This page ranks the 4 custom software development agencies in Illinois, United States that have been assessed on the Agency List Score, out of 32 listed.

The score measures how well an agency documents its own work in public — named clients, quantified outcomes, and whether those outcomes are attributed to the agency rather than described as the client's own results. It does not measure client satisfaction, price, or availability.

Cohorts and awards

Agencies are compared within a cohort — here, Custom Software Development in Illinois, United States. A cohort must be large enough to express the band being awarded: at least 8 assessed agencies for a top 25% award, 20 for top 10%, 40 for top 5%, and 300 for top 1%. This one holds 4, so no award can be issued here.

The 28 custom software development agencies not yet assessed are listed on this page but not ranked.

Read the full methodology

Paid placement

Partner agencies can buy a labelled placement block above the ranking on this page. It is always marked as paid and is never mixed into the ranked list.

Placement is paid; it does not affect the ranking, cohort membership, or any agency's score. Ranking position, cohort membership and the score itself are not for sale.

Browse

Questions

How many custom software development agencies are in Illinois, United States?
32 are listed on Agency List in Illinois, United States. 4 of them have been assessed on the Agency List Score as of September 2026.
Which custom software development agency in Illinois, United States is ranked highest?
Intersog, with an Agency List Score of 78.1, ranks #1 of 4 assessed agencies in Custom Software Development in Illinois, United States.
Why are 28 custom software development agencies listed here but not ranked?
28 of the 32 listed have not yet been assessed on the Agency List Score. They each have a profile and are listed below the ranking, alphabetically, rather than being hidden or mixed into it.
How is the ranking determined?
By Agency List Score, within the Custom Software Development in Illinois, United States cohort of 4 assessed agencies. The score is computed from evidence published on each agency's own website: named clients, quantified outcomes, and whether the outcome is attributed to the agency. Paid placement does not affect it.