On usedby, 27 companies use Blue J and 28 use Zest. No company is listed with both yet. Zest leads among the Banking & Mortgages companies on usedby that use either tool.Latest check Oct 7, 2026: 45 of 55 public lines checked. Counts include every proof level, job-post signals included. Companies named on both have a confirmed or observed line on each side.
Who uses Blue J, Zest, or both
Every company with a public proof for at least one of the two tools.
27
use only Blue J
0
companies use both
28
use only Zest
27 companies use only Blue J, 28 use only Zest and 0 use both, out of the 55 companies on usedby that use at least one of them.
Where it lands
Newest customers
No new customer since tracking started on October 7, 2026.
Where it lands
Newest customers
No new customer since tracking started on October 2, 2026.
Who uses both
Companies with a confirmed or observed line on both tools.
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
Blue J
ZestWhat customers report
Results as the vendor or the customer published them, with the source and the date.
Blue J
this user saving 6–8 hours per week on tax research
R2 Advisors
Vendor case study, bluej.com, captured Oct 7, 2026
Time Saved Per Week: Up to 5 hours/user
McKonly & Asbury
Vendor case study, bluej.com, captured Oct 7, 2026
Zest
No reviewed story for Zest yet.
Questions about Blue J and Zest
Which is used more, Blue J or Zest?
Zest has more customers on usedby: 28 against 27 for Blue J.
Do companies use both Blue J and Zest?
usedby has not found a company with a confirmed or observed line on both Blue J and Zest yet.
Who uses Blue J?
27 companies on usedby, each with the public page that shows it. See who uses Blue J.
Who uses Zest?
28 companies on usedby, each with the public page that shows it. See who uses Zest.
How does usedby count customers?
A company counts when a public page shows it: a vendor's customer page, a case study, a press release or a job post, most saved with a dated capture. Every line is a customer, at one of three proof levels: confirmed, observed or signal (a job post, the weakest). A company is named as using both tools when its lines on both are confirmed or observed.