Testlify vs Aon: A detailed comparison

Testlify is the stronger choice for a company that wants skills tests, AI video interviews and proctoring in one tool, with a price it can read off a page and a trial it can start today. Aon is the stronger choice for a multinational running high-volume graduate or leadership programmes that wants a consulting-led assessment partner, a validated personality model and a quote to match. This comparison walks both platforms feature by feature, using only what each vendor states on its own site, and answers the two questions readers keep landing here for: how Aon stacks up against SHL, and what the best Aon alternatives are.

TL;DR

• Aon Assessment Solutions is the enterprise psychometrics arm of Aon plc: ADEPT-15 personality, gamified cognitive challenges, timed ability tests, coding tasks and the vidAssess-AI one-way video interview, delivered at more than 30 million assessments a year in over 40 languages.
• Testlify is a pre-hire assessment and AI interviewing platform: 3,500+ tests, 25+ question types, conversational AI video, voice and phone interviews, three proctoring presets and published plans from $139 a month with a 7-day free trial.
• On breadth of question types, interview configurability, proctoring depth and price transparency, Testlify wins. On personality science, assessment-centre design and multinational programme support, Aon wins.
• SHL and Aon are peers, not opposites: both sell quote-only enterprise suites, both claim 80+ ATS integrations, and both are a heavy lift for a company under 200 people.
• In May 2024 the ACLU asked the FTC to investigate three Aon tools for bias. Whatever the outcome, ask any vendor for its adverse-impact data before you sign.

What is Aon Assessment Solutions?

Aon Assessment Solutions is the talent-assessment business inside Aon plc's Talent and Rewards practice. It grew out of Aon's acquisition of the German assessment firm cut-e, which is why candidates still search for "cut-e tests", and it now delivers more than 30 million assessments a year in over 40 languages across 90 countries. The catalogue covers ability and skills tests, behavioural questionnaires, coding challenges in 30+ programming languages, job simulations, remote proctoring, video assessments and virtual assessment centres.

Three products carry most of the brand. ADEPT-15 is Aon's behavioural assessment, built on 15 personality dimensions and used for both hiring and leadership development. The smartPredict family is a set of short gamified challenges, including gridChallenge, that measure cognitive capacity through interactive puzzles rather than word problems. And vidAssess-AI is a one-way video interview platform with a bank of over 600 questions, scored by AI against the competencies you select.

Aon sells to large employers through a consulting relationship. There is no self-serve signup, no free trial and no published price list; its assessments integrate with over 80 applicant tracking systems, and the buying motion runs through an account team that scopes a programme, validates it and rolls it out. That is a strength for a bank hiring 5,000 graduates a year and a real cost for a 40-person agency hiring four people this quarter.

What is the Aon assessment like for candidates?

Most candidates meet Aon through a timed online battery sent by an employer: one or more "scales" ability tests (numerical, verbal, abstract or logical reasoning), sometimes a gamified module such as gridChallenge, the ADEPT-15 personality questionnaire, and for some roles a vidAssess video interview recorded on your own device. The ability tests are timed and many are adaptive, so work quickly and accurately rather than aiming to reach the last item. Aon posts free practice tasks for the numerical tests on its own site, and it is worth doing them, because the item formats are unusual. Retake rules are set by the employer that invited you, not by Aon, so ask the recruiter before assuming you get a second attempt.

What is Testlify?

Testlify is a pre-hire assessment and AI interviewing platform. It ships a library of 3,500+ tests across coding, cognitive ability, language, personality, situational judgment, software skills and blue-collar trades, 25+ question types, AI video, voice and phone interviews with selectable avatars and voices, three proctoring presets, and 100+ ATS and HR integrations. Teams without an ATS also get a simple built-in hiring pipeline. Plans start at $139 a month billed annually, with a 7-day trial and a 30-day money-back window.

How does Testlify work?

Five steps, none of which needs a consultant.

1. Build the assessment

Pick tests from the library, choose from 150+ interview templates, or upload a job description and let the AI draft up to 20 questions for the role. A single invite can combine a skills test, a spreadsheet task inside the real Google Sheets or Excel, a coding problem in an embedded VS Code editor and an AI interview, each weighted from x0 to x5.

2. Configure the AI interviewer

Choose the AI avatar and voice, set a persona and context, write custom prompts, and decide how many attempts a candidate gets (or no limit), how long they can record (up to 5 minutes per answer) and how much preparation time they see before recording auto-starts. The same interview can run as a two-way conversational video, as audio, or as an outbound phone call billed at $0.18 a minute.

3. Invite and proctor

Invites go out by email, SMS or WhatsApp, in bulk or through a public link. Standard, Strict or Custom presets control the proctoring stack, from full-screen enforcement and webcam snapshots up to photo ID with face match and dual-device proctoring, where the candidate's phone becomes a second camera pointed at the desk.

4. Score with AI, decide as a human

Every recorded answer gets an automatic transcript in the spoken language, an AI score the reviewer can override, and an AI insights summary of strengths and gaps. The product's own disclaimer reads "AI scores and insights are for guidance only. Use human judgment for final decisions," and a toggle lets you leave AI scores out of the final average entirely.

5. Sync with the ATS

Testlify connects to 100+ ATS and HR platforms, including Workday, Greenhouse, Lever and SAP SuccessFactors, and can auto-advance a candidate to the next ATS stage when they clear a cut-off score. Your ATS stays the system of record. Testlify holds SOC 2 Type II and ISO 27001, is GDPR compliant, and deletes face-verification data after 30 days.

Testlify vs Aon: feature comparison

Every row below is something either vendor states on its own site or shows in its own product. Where a vendor publishes nothing, the cell says so rather than guessing. The old version of this page marked Aon as having no video interviewing; that was wrong, and it is fixed here.

Testlify vs Aon: test library and question types

Testlify is library-first. The 3,500+ tests sit in thirteen categories, from cognitive ability and psychometrics to role-specific skills and blue-collar trades, and any test can be extended with 25+ question types: single and multiple select, ranking, file upload, typing (scored 60% accuracy and 40% speed by default), practical hands-on tasks and Office-app questions that run inside the real Google Docs, Sheets, Slides, Word, PowerPoint and Excel. Question banks can draw a random subset per candidate, and per-question statistics (difficulty index, discrimination index, a "quality risk" flag) tell you when an item is not doing its job.

Aon is model-first. Its catalogue is organised around validated instruments (ADEPT-15, the scales ability series, smartPredict) and around programmes such as virtual assessment centres, rather than around a browseable test library. You get fewer, deeper instruments, each with a validation study behind it, and a consultant to map them to your competency model.

Verdict: Testlify for range and speed, Aon for instrument depth. A team that needs a Google Sheets task for a finance hire and a typing test for a support hire on the same afternoon wants Testlify. A team building a leadership pipeline across 20 countries on one personality model wants Aon.

Testlify vs Aon: AI video interviewing

Aon sells vidAssess-AI, an asynchronous video interview platform with a bank of over 600 questions. Candidates record answers on their own device and the AI scores the responses against the competencies you selected for the role.

Testlify runs interviews in four formats from the same assessment. One-way video works like vidAssess. Video AI puts a selectable avatar with a named voice in front of the candidate for a real two-way conversation, with the candidate muted while the AI speaks. Voice AI runs the same interview over audio, and the phone mode dials the candidate on a real handset. You set the persona, the prompts, the number of attempts, the preparation time and the recording cap per question, and every answer gets a multilingual transcript, an AI score the reviewer can override and an interview report. Video violation detection (webcam off, no face, multiple faces) runs inside the interview itself.

Verdict: Testlify, on configurability and on format. Aon's one-way tool is a solid competency screen; Testlify adds the conversational and phone modes and puts every dial in the recruiter's hands. Neither vendor schedules live human interview panels for you.

Testlify vs Aon: proctoring and anti-cheating

Gartner's 2025 survey of 3,000 job candidates found that 6% admitted to interview fraud, either posing as someone else or having someone sit in for them, and Gartner projects that 1 in 4 candidate profiles worldwide will be fake by 2028. Proctoring depth is no longer a nice-to-have.

Testlify answers with three presets over a long list of controls: face detection and single-presence checks, photo ID with face match, webcam snapshots at a configurable interval, screen and camera recording, session recording of clicks and navigation, copy-paste and screenshot tracking, tab-switch and mouse-out detection, multi-monitor restriction, AI-tool and browser-extension detection, IP and location checks, talking prohibition, and dual-device proctoring where the candidate's phone streams a second view of the desk. Every session is graded green, yellow ("a quick manual review is recommended") or red, and auto-termination is a separate opt-in with its own threshold. A flag is evidence for a human to weigh, not a verdict.

Aon lists remote proctoring as a product and says it works on mobile devices, but the public product page does not describe which signals it captures, whether it verifies identity against an ID, or how strictness is tuned per role. Ask for the specification.

Verdict: Testlify, on what is published. Aon may match some of this in a scoped programme, but you cannot check it from the website, and you can check every Testlify control in the trial.

Testlify vs Aon: fairness, bias and compliance

This is the section the old version of this page skipped, and it is the one a careful buyer should read twice. On 30 May 2024 the American Civil Liberties Union filed a complaint with the US Federal Trade Commission alleging that Aon markets three products, its ADEPT-15 personality assessment, the vidAssess-AI video tool and the gamified gridChallenge, as "bias-free" and able to "improve diversity" while, in the ACLU's reading, they are likely to disadvantage candidates by race or disability. A complaint is an allegation, not a finding. But it changes the questions you ask on the sales call.

The yardstick in the United States is the Uniform Guidelines on Employee Selection Procedures, 29 CFR Part 1607: a selection rate for any group below four-fifths (80%) of the rate for the highest group is generally treated as evidence of adverse impact. New York City's Local Law 144 adds an independent bias audit within the past year and candidate notice before an automated tool is used, and the EU's Artificial Intelligence Act classifies AI used to recruit, screen or evaluate candidates as high-risk under Annex III.

Testlify builds for that posture in the product: the "AI scores and insights are for guidance only" disclaimer, the toggle that excludes AI scores from the final average, manual-review routing to a named human, anonymous and skippable DEI data collection, a candidate-initiated accommodation request that goes to a human administrator, and disqualification reasons that are disclosed rather than silent. Face-verification data is deleted after 30 days. Aon positions its instruments on validation studies; what you should request is the adverse-impact analysis for your candidate population and the audit report if you hire in New York.

Verdict: Neither vendor gets a free pass, because no assessment is bias-free by decree. Testlify makes human override a default and shows you the controls; with Aon, get the evidence in writing.

Testlify vs Aon: integrations and workflow

Aon integrates with over 80 applicant tracking systems, which for an enterprise buyer is the number that matters, and its programmes are implemented by an account team. Testlify integrates with 100+ ATS and HR platforms with two-way sync of candidates, stages and scores, plus Zapier, webhooks and an API, and candidates can auto-advance to the next ATS stage on a cut-off score. Be clear-eyed on cost: on the Starter, Basic and Business plans the ATS integration pack is a $2,388 per year add-on, included on Custom. Teams with no ATS get a mini pipeline instead: post the job, take applications, move candidates from applied to shortlisted.

Verdict: Even on connector count. Testlify wins on self-serve setup and on having a pipeline for companies that run hiring out of a spreadsheet today.

Testlify vs Aon: pricing

Aon does not publish prices. Every engagement is scoped and quoted, there is no self-serve tier and no free trial, and third-party directories that print a starting figure are estimating, not quoting Aon. Budget for an annual programme fee plus implementation time from your own HR and IT teams.

Testlify publishes its pricing plans in US dollars. One credit is spent per candidate who starts an assessment, credits do not roll over, and every tier includes a 7-day trial with no card, a 30-day money-back guarantee and a 24-month price lock.

Extra seats are $15 per user per month on every tier, AI phone interviews are metered at $0.18 a minute, and the two enterprise add-ons (100+ ATS integrations and white labeling) are $2,388 per year each on the self-serve tiers. Non-profits get 25% off.

Verdict: Testlify on transparency, and on total cost below enterprise volume. A worked example: a 45-person marketing agency screening 200 applicants for four client-services roles this year would use 200 of the 300 credits on Testlify's Basic plan, $3,348 for the year, and every one of those candidates could sit a writing task, a spreadsheet test and an AI interview on the same credit. The same team asking Aon for a quote is asking an enterprise account team to scope a programme for four hires. At 25,000+ candidates a year the conversation changes, and both vendors put you on a custom contract.

Pro tip: Whichever vendor you choose, run a shadow test before you switch. Assess your last 20 hires and your last 20 rejected finalists with the new tool and check whether the scores separate the two groups. If they do not, the tool is measuring something other than performance in your roles, and no brand name fixes that.

SHL vs Aon: which is better for hiring assessments?

SHL and Aon are the two most comparable enterprise assessment vendors on the market, and for most large employers the honest answer is that either will do the job; the choice turns on personality model, existing ATS and account-team fit. SHL states that 45 million SHL assessments are taken every year, that it serves over 10,000 businesses and integrates with 80+ ATS, and that its instruments are developed by 300+ people scientists. Aon states more than 30 million assessments a year, 40+ languages, 90 countries and 80+ ATS integrations. Neither publishes a price. Neither offers a free trial.

Where they differ is the flagship instrument and the shape of the catalogue. SHL's core is the Occupational Personality Questionnaire (OPQ) and the SHL Verify interactive cognitive tests, backed by the Global Skills Assessment, a Motivational Questionnaire, situational judgment tests, job-focused assessments, coding and call-centre simulations, video interviews and SHL 360. Aon's core is ADEPT-15 and the scales ability series, backed by gamified smartPredict modules, coding challenges, job simulations, vidAssess-AI and virtual assessment centres. If your organisation already speaks OPQ, SHL is the path of least resistance; if it already runs cut-e or ADEPT-15 for development, Aon is.

Pick SHL when you want the larger skills-assessment catalogue and a 360 tool in the same suite. Pick Aon when gamified cognitive measurement and assessment-centre design matter more than catalogue size. Pick neither when you are under about 200 employees and need something live this week: at that size the implementation effort outweighs the instrument depth, and Testlify's self-serve plans and 7-day trial are the better fit. The full head-to-head is in our Testlify vs SHL comparison, and the SHL alternatives guide covers the wider field.

What are the best alternatives to the Aon assessment?

The best Aon alternative depends on your size and your buying motion. For companies under about 200 employees, Testlify is the strongest alternative: a 3,500+ test library, conversational AI video, voice and phone interviews, proctoring you can tune per role, 100+ integrations and a published price with a trial, all without a consulting engagement. For a multinational that wants a like-for-like enterprise suite with a validated personality model and an account team, SHL is the closest peer. Our guide to the top Aon alternatives compares 15 platforms across pricing, library size and proctoring if you want the wider field.

Three questions narrow the list fast. How many candidates will you assess this year (under 1,000 points to a self-serve credit plan)? Do you already run an ATS you trust (then integration depth matters more than a built-in pipeline)? And do you need a personality instrument with a published validation study, or do you need work samples that show what a candidate can actually do? The 2022 reanalysis of selection-method validity by Sackett and colleagues in the Journal of Applied Psychology puts structured interviews (.42), work samples (.33) and cognitive ability (.31) among the strongest predictors of job performance and personality measures well below them, which is a good reason to treat a personality-led suite as one signal among several rather than the centre of the process.

Is Testlify the best Aon alternative?

For a company under about 200 employees, and for any team that hires across more than one job family, yes. Testlify is the best Aon alternative because it covers more of the hiring decision in one tool: the same one-way video interview Aon offers, plus conversational, voice and phone modes, a 3,500+ test library that includes real work samples, a proctoring stack you can tune per role, 100+ ATS connectors you can inspect before buying, and a simple pipeline for teams with no ATS at all. The Testlify Multi-Signal Talent Evaluation Model is the reason that breadth matters: a candidate should move forward when a skills test, a work sample, an AI interview and a reviewer's structured feedback all point the same way, not because one personality profile matched a template.

That model also happens to be the compliance-friendly one. A process built on several role-relevant signals, with AI scores marked advisory and a human making the final call, is easier to defend under the four-fifths rule, Local Law 144 and the EU AI Act than a process that leans on a single instrument, whoever sells it.

When is Aon the better pick?

Three honest cases. First, you run a graduate or early-careers programme across many countries and want one validated personality model, gamified cognitive modules and virtual assessment centres designed and normed by a consulting team; that is Aon's home ground, and Testlify is a self-serve platform rather than a consulting practice. Second, your organisation already uses ADEPT-15 or cut-e instruments for leadership development and you want hiring on the same model so the data joins up. Third, you are a 5,000-person employer whose procurement process expects an enterprise vendor with a global services team, and the price of a scoped programme is not the constraint.

The trade you make is agility and transparency. No self-serve setup, no trial, no price list, a thinner published proctoring specification, and an open regulatory question you will need to ask about directly.

Ready to see the difference on your own roles? Book a demo with Testlify, or start the 7-day free trial and run one real skills test plus an AI interview on your next opening this week. The comparison that matters is the one on your candidates.

Key takeaways

• Aon is an enterprise psychometrics partner, not a self-serve tool. More than 30 million assessments a year, 40+ languages, 90 countries and a consulting-led rollout make it a strong fit for multinational programmes and a poor fit for a small team that needs something live this week.
• Testlify wins on breadth and configurability. 3,500+ tests, 25+ question types including Office-app tasks and coding in a real editor, four interview formats with avatar, voice and attempt controls, and three proctoring presets, all visible in a 7-day trial before you pay.
• Aon does have AI video interviewing. vidAssess-AI is a one-way tool with a 600+ question bank scored by AI; the old checkmark table on this page said otherwise and was wrong. Testlify adds conversational, voice and phone modes on top.
• Ask both vendors for bias evidence. The ACLU's May 2024 FTC complaint names three Aon tools; the four-fifths rule, NYC Local Law 144 and the EU AI Act set the bar. Testlify ships advisory-only AI scores and human override as defaults, which is what an auditor will ask to see.
• SHL and Aon are peers. 45 million versus 30 million assessments a year, 80+ ATS each, quote-only pricing on both. Choose on personality model (OPQ versus ADEPT-15) and on which suite your organisation already runs, not on marketing claims.
• Price transparency is a feature. Testlify's Basic plan is $3,348 a year for 300 credits with every candidate able to sit a test, a work sample and an interview on one credit; Aon quotes per programme. Below enterprise volume that gap decides most deals.
• Candidates: the Aon battery is timed and adaptive. Work fast and accurately rather than aiming to finish, do the practice tasks, and ask the recruiter about retakes, because the employer sets that rule.

FAQs