Chai Assertion Library (Chai.js)
UK

The table below provides summary statistics for permanent job vacancies requiring Chai skills. It includes a benchmarking guide to the annual salaries offered in vacancies that cited Chai over the 6 months leading up to 27 August 2025, comparing them to the same period in the previous two years.

6 months to
27 Aug 2025
Same period 2024 Same period 2023
Rank 698 818 783
Rank change year-on-year +120 -35 +170
DemandTrendPermanent jobs citing Chai 2 12 31
As % of all permanent jobs advertised in the UK 0.004% 0.014% 0.044%
As % of the Libraries, Frameworks & Software Standards category 0.022% 0.073% 0.16%
Number of salaries quoted 1 7 26
10th Percentile - - £42,375
25th Percentile £41,250 - £48,750
Median annual salary (50th Percentile) £42,500 £42,500 £70,000
Median % change year-on-year - -39.29% +27.27%
75th Percentile £43,750 £91,250 £75,000
90th Percentile - - £87,500
UK excluding London median annual salary - £42,500 £50,000
% change year-on-year - -15.00% -9.09%

All Software Libraries and Frameworks
UK

Chai falls under the Software Libraries and Frameworks category. For comparison with the information above, the following table provides summary statistics for all permanent job vacancies requiring technical specification, industry standards, software libraries and framework skills.

DemandTrendPermanent vacancies with a requirement for technical specification, industry standards, software libraries and framework skills 9,149 16,524 18,980
As % of all permanent jobs advertised in the UK 16.52% 19.18% 26.81%
Number of salaries quoted 5,401 11,173 14,486
10th Percentile £38,750 £37,500 £41,250
25th Percentile £50,000 £46,500 £51,250
Median annual salary (50th Percentile) £67,500 £62,500 £67,500
Median % change year-on-year +8.00% -7.41% +3.85%
75th Percentile £87,500 £81,250 £85,000
90th Percentile £113,750 £107,500 £106,250
UK excluding London median annual salary £57,500 £55,000 £57,500
% change year-on-year +4.55% -4.35% +4.55%

Chai
Job Vacancy Trend

Job postings citing Chai as a proportion of all IT jobs advertised.

Job vacancy trend for Chai in the UK

Chai
Salary Trend

Salary distribution trend for jobs in the UK citing Chai.

Salary distribution trend for jobs in the UK citing Chai

Chai
Top 2 Job Locations

The table below looks at the demand and provides a guide to the median salaries quoted in IT jobs citing Chai within the UK over the 6 months to 27 August 2025. The 'Rank Change' column provides an indication of the change in demand within each location based on the same 6 month period last year.

Location Rank Change
on Same Period
Last Year
Matching
DemandTrendPermanent
IT Job Ads
Median Salary
Past 6 Months
Median Salary
% Change
on Same Period
Last Year
Live
Jobs
England +89 2 £42,500 -
London +61 2 £42,500 -51.43%

Chai
Co-occurring Skills and Capabilities by Category

The follow tables expand on the table above by listing co-occurrences grouped by category. The same employment type, locality and period is covered with up to 20 co-occurrences shown in each of the following categories:

Cloud Services
1 1 (50.00%) Figma
Development Applications
1 2 (100.00%) Grunt
1 2 (100.00%) Mocha
2 1 (50.00%) gulp
2 1 (50.00%) Jasmine
2 1 (50.00%) webpack
General
1 1 (50.00%) Banking
1 1 (50.00%) Finance
1 1 (50.00%) Inclusion and Diversity
1 1 (50.00%) Retail Banking
Job Titles
1 2 (100.00%) Developer
2 1 (50.00%) Front-End Developer (Client-Side Developer)
2 1 (50.00%) Lead
2 1 (50.00%) Lead Developer
2 1 (50.00%) React Developer
2 1 (50.00%) UX Developer
Libraries, Frameworks & Software Standards
1 2 (100.00%) CSS
1 2 (100.00%) LESS
1 2 (100.00%) React
1 2 (100.00%) Sass
1 2 (100.00%) Vue
2 1 (50.00%) Ajax
2 1 (50.00%) AngularJS
2 1 (50.00%) Bootstrap
2 1 (50.00%) Enzyme
2 1 (50.00%) HTML
2 1 (50.00%) Jest
2 1 (50.00%) JWT
2 1 (50.00%) Material-UI
2 1 (50.00%) Next.js
2 1 (50.00%) Node.js
2 1 (50.00%) OAuth
2 1 (50.00%) OAuth2
2 1 (50.00%) OpenID
2 1 (50.00%) Redux
2 1 (50.00%) Semantic UI
Processes & Methodologies
1 2 (100.00%) Responsive Web Design
2 1 (50.00%) Agile
2 1 (50.00%) Asset Management
2 1 (50.00%) Business Case
2 1 (50.00%) CI/CD
2 1 (50.00%) Coaching
2 1 (50.00%) Containerisation
2 1 (50.00%) Continuous Improvement
2 1 (50.00%) Design Patterns
2 1 (50.00%) Front End Development
2 1 (50.00%) Mentoring
2 1 (50.00%) Stakeholder Management
2 1 (50.00%) Test Strategy
2 1 (50.00%) Thought Leadership
2 1 (50.00%) Usability Testing
2 1 (50.00%) Use Case
2 1 (50.00%) User Experience
2 1 (50.00%) User Research
2 1 (50.00%) Wireframes
Programming Languages
1 2 (100.00%) JavaScript
1 2 (100.00%) TypeScript
Quality Assurance & Compliance
1 1 (50.00%) Accessibility
System Software
1 1 (50.00%) Docker
Systems Management
1 1 (50.00%) Kubernetes