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 12 June 2025, comparing them to the same period in the previous two years.

6 months to
12 Jun 2025
Same period 2024 Same period 2023
Rank 707 899 898
Rank change year-on-year +192 -1 +85
Permanent jobs citing Chai 7 9 38
As % of all permanent jobs advertised in the UK 0.013% 0.008% 0.041%
As % of the Libraries, Frameworks & Software Standards category 0.072% 0.041% 0.14%
Number of salaries quoted 1 4 22
10th Percentile - - £40,275
25th Percentile £41,250 - £46,563
Median annual salary (50th Percentile) £42,500 £42,500 £65,000
Median % change year-on-year - -34.62% +18.18%
75th Percentile £43,750 - £72,500
90th Percentile - - £75,000
UK excluding London median annual salary - £42,500 £50,000
% change year-on-year - -15.00% -3.85%

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.

Permanent vacancies with a requirement for technical specification, industry standards, software libraries and framework skills 9,720 21,956 26,964
As % of all permanent jobs advertised in the UK 17.42% 20.06% 29.03%
Number of salaries quoted 5,837 16,256 17,630
10th Percentile £37,574 £36,250 £40,500
25th Percentile £51,250 £45,000 £50,000
Median annual salary (50th Percentile) £66,254 £60,000 £67,500
Median % change year-on-year +10.42% -11.11% +3.85%
75th Percentile £86,250 £78,750 £87,500
90th Percentile £111,250 £100,000 £106,250
UK excluding London median annual salary £60,000 £55,000 £57,500
% change year-on-year +9.09% -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

3-month moving average salary quoted in jobs citing Chai.

Salary trend for Chai in the UK

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 12 June 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
Permanent
IT Job Ads
Median Salary
Past 6 Months
Median Salary
% Change
on Same Period
Last Year
Live
Jobs
England +155 7 £42,500 - 2
London +105 7 £42,500 -

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 (14.29%) Figma
Development Applications
1 7 (100.00%) Grunt
1 7 (100.00%) Mocha
2 6 (85.71%) Jasmine
2 6 (85.71%) webpack
3 1 (14.29%) gulp
General
1 6 (85.71%) Banking
1 6 (85.71%) Finance
1 6 (85.71%) Inclusion and Diversity
1 6 (85.71%) Retail Banking
Job Titles
1 7 (100.00%) Developer
2 6 (85.71%) Front-End Developer (Client-Side Developer)
2 6 (85.71%) Lead
2 6 (85.71%) Lead Developer
2 6 (85.71%) React Developer
3 1 (14.29%) UX Developer
Libraries, Frameworks & Software Standards
1 7 (100.00%) CSS
1 7 (100.00%) LESS
1 7 (100.00%) React
1 7 (100.00%) Sass
1 7 (100.00%) Vue
2 6 (85.71%) Ajax
2 6 (85.71%) AngularJS
2 6 (85.71%) Bootstrap
2 6 (85.71%) Enzyme
2 6 (85.71%) Jest
2 6 (85.71%) JWT
2 6 (85.71%) Material-UI
2 6 (85.71%) MobX
2 6 (85.71%) Next.js
2 6 (85.71%) OAuth
2 6 (85.71%) OAuth2
2 6 (85.71%) OpenID
2 6 (85.71%) Redux
2 6 (85.71%) Semantic UI
3 1 (14.29%) Node.js
Processes & Methodologies
1 7 (100.00%) Responsive Web Design
2 6 (85.71%) Agile
2 6 (85.71%) Asset Management
2 6 (85.71%) Business Case
2 6 (85.71%) CI/CD
2 6 (85.71%) Coaching
2 6 (85.71%) Containerisation
2 6 (85.71%) Continuous Improvement
2 6 (85.71%) Design Patterns
2 6 (85.71%) Front End Development
2 6 (85.71%) Mentoring
2 6 (85.71%) Stakeholder Management
2 6 (85.71%) Test Strategy
2 6 (85.71%) Thought Leadership
2 6 (85.71%) Use Case
3 1 (14.29%) Usability Testing
3 1 (14.29%) User Experience
3 1 (14.29%) User Research
3 1 (14.29%) Wireframes
Programming Languages
1 7 (100.00%) JavaScript
1 7 (100.00%) TypeScript
Quality Assurance & Compliance
1 1 (14.29%) Accessibility
System Software
1 6 (85.71%) Docker
Systems Management
1 6 (85.71%) Kubernetes