Two different categories, honestly
TestGorilla and Prelim get compared because both promise to screen candidates before a recruiter spends time on them. They go about it in opposite ways. TestGorilla is a pre-employment testing platform: you assemble a battery of standardized tests, candidates take them, and you get objective scores to rank. Prelim is a conversational screening interview: you paste a job description, the AI generates role-specific questions, and candidates answer in a short text conversation that gets scored for fit.
Neither is enterprise-priced or hard to start, so this is not a comparison about cost or complexity. It is about what you are trying to learn from a candidate before you talk to them. If the answer is "can they pass a specific, testable skill," TestGorilla is built for that. If the answer is "can this person do this job, are they qualified, and are they actually available," a conversational screen fits better. Both can be right. The mistake is using one for the other's job.
What TestGorilla actually is
TestGorilla is a skills-testing library. You build an assessment by picking from hundreds of tests: cognitive ability, personality and culture, situational judgment, software and role-specific skills, language proficiency, typing speed, coding challenges. Candidates complete the battery, often three to five tests in one sitting, and you get percentile scores you can sort and compare. The core pitch is replacing resume screening with objective measurement. Instead of guessing from a CV, you test the skill directly and rank by result.
For roles where a specific skill is the gate, that is a strong model. If you are hiring a bookkeeper and Excel proficiency is non-negotiable, a graded Excel test tells you more than any interview answer. If you are hiring a junior developer, a coding challenge is real signal. TestGorilla does objective, standardized, comparable measurement well, and the anti-bias framing of testing the work instead of the resume is legitimate.
What Prelim does instead
Prelim does not test abstract aptitude. It runs a conversational screening interview built from your actual job description. Paste the JD, and the AI writes role-specific questions: the certifications the role requires, the shift availability you need, the scenarios the person will actually face on the job. The candidate answers in their own words, in a text conversation on any phone, and you get a scored transcript with a strong-yes / yes / maybe / no recommendation.
The bet is that for most high-volume hourly hiring, the screening question is not "what is this candidate's cognitive percentile." It is "are they certified, can they work the shifts, will they show up, and can they handle the basic judgment calls the job involves." Those answers do not come from a test battery. They come from asking the actual job questions, which is what a structured conversational screen does.
The deciding question: skill or fit
This is the whole comparison, so be honest about which side your roles fall on.
A test battery is the right tool when a clean, testable skill is the thing that decides the hire. Typing speed for a data-entry role. Coding for an engineer. Numerical reasoning for an analyst. Software proficiency for a specialist. These are objectively measurable, and a graded test beats a conversation every time.
A conversational screen is the right tool when the hire is decided by fit, qualifications, and reliability rather than an aptitude score. A CNA is hired on their license, their comfort with residents, and whether they can work overnights, not on a cognitive percentile. A warehouse associate is hired on availability, reliability, and whether they can handle the physical demands. A CDL driver is hired on endorsements, a clean record, and route fit. None of that is a test-library item. It is a set of job-specific questions, and asking them directly is faster and more accurate than inferring fit from a personality test.
Completion is the hidden cost of a test battery
There is a second problem with tests for high-volume hourly hiring, and it is the one that quietly kills funnels: completion.
A useful screen is one candidates actually finish. A three-to-five-test battery can run twenty to forty-five minutes and feels like an exam, because it is one. For a salaried knowledge worker chasing a competitive role, that friction is acceptable. For an hourly candidate applying to five jobs from their phone on a break, it is the moment they close the tab. Asynchronous text screening tends to complete at 60 to 80 percent for hourly roles because it is short, conversational, and mobile-native. A long test battery completes far lower, and every candidate who abandons is one you never got to evaluate. More on where applicants leak out in our note on candidate drop-off.
If you are filling forty caregiver roles, a screen that 70 percent of applicants finish gives you a very different shortlist than one 30 percent finish. At high volume, completion is not a nice-to-have. It is the size of your funnel.
Where TestGorilla is genuinely better
Be clear about where tests win, because they clearly do for some hiring.
Objective skill measurement. If you need to know a candidate can actually code, type 60 words per minute, or use Excel at a real level, a graded test proves it and a conversation does not. This is TestGorilla's core strength, and Prelim does not try to compete on it.
Standardized, comparable scores. When you are ranking a large pool on the same dimensions, percentile scores from an identical test are cleanly comparable. A conversational screen scores role fit, which is the right signal for fit but not a substitute for a normed aptitude score.
Proctoring and anti-cheat. TestGorilla offers webcam snapshots, time limits, and other controls to protect test integrity. If the validity of the score depends on the candidate not cheating, that infrastructure matters.
Skill-gated knowledge roles. For a role like an IT help desk technician, where a specific technical skill is the bar, a skills test is real signal and a sensible first filter.
Where Prelim wins
Role-specific questions, not library items. Prelim asks about the actual job: the certification, the shift, the scenario. You are not approximating fit from a standardized test, you are asking the question directly.
Setup in seconds. Paste a job description and the screen is ready. There is no assessment to assemble from a test library, no decision about which five tests to combine, no validation work. For a team running many different roles, that speed compounds.
Mobile-native and high-completion. Your candidates screen from their phones between shifts. A short conversational screen fits that reality. A timed test battery does not, and completion shows it.
Readable output. A scored transcript with a clear recommendation takes about two minutes to review and tells you why the candidate fits. Percentile scores across five tests need interpretation before they tell you whether to advance someone.
You can use both
These are not mutually exclusive, and for some pipelines the right answer is both. Use a conversational screen as the high-volume first filter to confirm qualifications, availability, and fit, then send the short list that needs a hard-skill check into a targeted test. Screen first on the things that disqualify most applicants (not certified, cannot work the shift, not actually interested), then test the few who clear that bar on the specific skill that matters. That sequence respects both candidate time and yours.
Which one fits you
Pick TestGorilla when a specific, testable skill decides the hire, when you need standardized comparable scores across a large pool, or when proctored skill measurement is the point. It does objective testing well, and for skill-gated roles it is the better tool. At the enterprise tier, evaluate it alongside suites like HireVue.
Pick Prelim when you hire high-volume hourly or service roles where fit, qualifications, and availability decide the hire, and when completion on mobile is your real constraint. The same logic that makes a conversational screen beat a long video interview against Willo applies to test batteries, for the same reason: lower friction, higher completion, more candidates actually screened. Start free, paste a job description, and share the link: create an account. We have ready-built screens for most hourly roles, including warehouse associate, CDL driver, and CNA, plus vertical guides for warehouse and logistics, senior living, and retail hiring.