Best coding interview platforms in 2026, 8 compared by format and price

Key takeaways

LeetCode is the default problem bank for raw volume, and NeetCode's pattern roadmap is the best free structured path. If you can already solve problems but freeze when you have to explain one, Four-Leaf runs voice-based conversational interviews with a code editor at $20 a month or a $5 one-time pass, and Interviewing.io sells live mocks with senior engineers, from $179 a session, for a few high-stakes reps.

Prefer to watch. The 76-second version is above. The full breakdown is below.

Quick picks

If you just want the answer.

• Best problem bank is LeetCode. The largest set of typed problems and the company-tagged filter on Premium make it the default for raw volume.
• Best free structured path is NeetCode. The pattern-organized roadmap and video solutions are the strongest free starting point.
• Best for talking through problems out loud is Four-Leaf at $20 a month, or a $5 one-time 5 Day Pass. Voice-based conversational interviews with a code editor and scored feedback, on demand.
• Best live human practice is Interviewing.io. Senior engineers from major tech companies, anonymous, the closest thing to the real onsite. From $179 per session.
• Best on-platform practice is HackerRank. It is the engine many employers use for the real assessment, and its candidate side now runs AI mock interviews.

The rest of this post breaks each one down by format.

What actually matters in a coding interview tool

Before the list, here is what we evaluated.

Format. Typing a solution in silence and explaining one out loud are different skills. A tool that only does the first leaves you unprepared for the second. We weighted format heavily because the live interview grades both.

Feedback depth. Some tools tell you whether your tests passed. Better ones tell you about your approach, your complexity, your code quality, and how clearly you communicated. The second kind moves your interview score.

Problem quality and coverage. A strong pattern library that mirrors what real companies ask is worth more than sheer count. We looked at how well each tool's problems map to actual interviews.

Cost per rep. A free roadmap, a flat monthly subscription, and a per-session live mock are very different economics. Each fits a different stage and budget.

LeetCode

LeetCode is the category default for a reason. The problem bank runs to thousands of typed problems with full test cases, and the Premium tier adds company-tagged questions so you can drill the patterns a specific employer tends to ask. For building raw problem-solving volume, it is the default.

You solve problems in a typed editor and run them against test cases. There is no interviewer, no voice, no feedback on how you would come across in a real conversation. That is the strength and the limit at once. LeetCode makes you faster at finding solutions. It does nothing for the spoken delivery the onsite actually grades.

Pricing has a free tier plus a paid Premium subscription on monthly or annual billing. The fit is anyone building pattern volume, especially with a specific company in mind.

Four-Leaf

Four-Leaf is built around the format the typed tools skip. In its conversational mode, a coding round runs as a spoken conversation with a code editor alongside it. You hear the problem, talk through your approach, and write the solution, the way a real onsite plays out. The written debrief afterward scores each topic on relevance, specificity, structure, role fit, and communication. A separate question-by-question mode takes a coding answer in the editor and scores the code from 1 to 10 on correctness, syntax, structure, efficiency, and style, with a short note on each.

The spoken part is the point. Going silent, jumping to code without stating a plan, or failing to defend a trade-off when pushed can sink a round you could have solved on paper. Talking through a problem out loud is a trainable skill, and it is hard to train against a text editor. Four-Leaf lets you run that rehearsal on demand, with coding rounds configured for roles including software engineering, frontend, full-stack, data engineering, and mobile.

Beyond coding rounds, Four-Leaf covers system design and behavioral practice, plus the rest of the job search: resume tailoring, cover letters, AI job discovery, and salary negotiation. It is one subscription for the whole pipeline.

The honest tradeoff is that Four-Leaf is conversational practice without a code-execution sandbox, so it does not replace running your code against test cases or the sheer problem volume of LeetCode. The strongest prep pairs the two. Use a problem bank to build the patterns and Four-Leaf to rehearse explaining them out loud under pressure.

Pricing has two paths. The 5 Day Pass at $5 is a one-time purchase for a single upcoming interview, no auto-renewal, full access for five days. Pro at $20 a month is the recurring plan, with a 3-day free trial. Both include every feature. The fit is candidates who can solve problems but want to rehearse the spoken delivery the interview actually scores.

NeetCode

NeetCode is the best free starting point. The core product is a curated roadmap, the NeetCode 150 and Blind 75, organized by pattern rather than dumped as a flat list. Each problem comes with a clear video walkthrough. For a self-directed learner who wants structure without paying, it is hard to beat.

The pattern organization is the value. Instead of grinding random problems, you work through arrays, then two pointers, then sliding window, then trees, building the mental library in the order that actually compounds. A paid Pro tier adds courses and extra content.

Like LeetCode, NeetCode is typed, solo study. There is no spoken practice and no interviewer. Pair it with a conversational or live mock once your patterns are solid.

Pricing has a free core roadmap plus a paid Pro tier. The fit is self-directed learners who want a structured, no-cost path through the essential patterns.

Interviewing.io

Interviewing.io is the strongest option for live human practice. Its interviewers are Senior, Staff, or Principal-level engineers or engineering managers at FAANG and FAANG-adjacent companies, you stay anonymous, and you talk through the problem live with a person who runs these loops for a living. It covers algorithms, system design, machine learning, front-end, behavioral, and manager interviews, and it also offers an AI Interviewer you can try for free.

The feedback is the differentiator. It comes from an engineer who interviews for a living.

The limitation is cost. Per its FAQ, premium interviews start at $179 per session, with prices varying by subject and by whether you pick an interviewer from a specific company. That makes it a tool for a few high-stakes reps right before a real interview rather than daily practice.

Pricing starts at $179 per session, with multi-session coaching programs available. The fit is candidates who want the most realistic spoken practice with real engineers and can budget for a small number of sessions.

AlgoExpert

AlgoExpert offers a curated problem set with video explanations and an in-browser editor. The pitch is curation over firehose. It offers a hand-picked set that covers the important patterns, each with a walkthrough, instead of LeetCode's thousands. System design is sold as a separate product.

For someone who finds LeetCode's volume overwhelming, the smaller explained set is easier to actually finish. The video explanations are solid. The format is still typed, solo practice with no interviewer or spoken component.

Pricing is an annual subscription, with a bundle option for system design. The fit is candidates who want a curated, explained problem set rather than an open-ended bank.

Aced (formerly Exponent)

Aced is the new name for Exponent, and it is also where Pramp's peer mock interviews now run. It combines structured courses with live peer practice. You schedule a session, get matched with another candidate, and interview each other over video, with peer sessions covering data structures and algorithms, system design, SQL, frontend, and data science and ML. AI mock interviews and AI feedback sit in the Expert tier.

The course content is strong for software engineering and the peer format gives you live spoken reps at a fraction of the cost of professional mocks. The tradeoff is peer quality. Your interviewer is another candidate, not a vetted engineer, so the feedback varies.

Pricing starts with a free Basic tier that includes five peer mocks a month. Pro is $79 a month or $149 charged yearly, and Expert, which adds the AI practice, is $99 a month or $249 charged yearly. The fit is candidates who want live spoken practice and structured courses without paying per session.

CodeSignal

CodeSignal is two products. The best known is the assessment engine employers use for the real screen, so practicing on it means practicing on the actual platform. The individual product, CodeSignal Learn, is practice-based skill building with an AI tutor.

For familiarity with the assessment format some employers use, CodeSignal is useful. The individual learning product is more of a skill-builder than a mock-interview simulator, so it sits alongside, not instead of, spoken practice.

Pricing has a free tier plus a paid individual plan; CodeSignal's pricing page does not render to our checker, so confirm the current price there. The fit is candidates who want to practice on the same engine employers use, plus AI-tutored skill paths.

HackerRank

HackerRank, like CodeSignal, is primarily the platform employers send candidates for the real assessment. On the candidate side it now runs AI mock interviews, timed sessions for coding, system design, frontend, backend, behavioral, and AI fluency rounds, with feedback HackerRank describes as covering "your approach, code, and communication."

The value is familiarity. If a target employer uses HackerRank for its screen, practicing on it removes the surprise factor. The practice is less structured than a curriculum like NeetCode, so it works best as a supplement.

Its mock interview page does not state a price, so check before you start. The fit is candidates practicing for an employer that uses HackerRank, or anyone who wants reps on the real assessment engine.

The real question, can you solve it or can you explain it

Here is the practical split. Are you failing to find solutions, or failing to communicate them?

If you cannot reliably solve medium problems yet, the bottleneck is patterns. Spend your time in a problem bank. NeetCode for a free structured path, LeetCode for volume and company-tagged drilling, AlgoExpert for a curated explained set. Build the library first.

If you can solve problems on paper but freeze, ramble, or go silent in the actual interview, the bottleneck is delivery. That is a spoken skill, and you train it by speaking. A conversational AI tool like Four-Leaf gives you reps on demand, and a live mock from Interviewing.io gives you a smaller number of high-realism reps with a real engineer. Many candidates need both kinds of work, and the order matters. Patterns come first, then delivery.

How we compared

We evaluated each tool on format, feedback depth, problem quality, and price. Prices for Four-Leaf, Aced, and Interviewing.io come from our verified pricing records, and Four-Leaf's features were checked against its own code. Details for the other tools come from their public sites, and where a vendor does not publish a number on a readable page we describe the model rather than guess. Tool pricing changes often, so confirm on the vendor's page before you buy. There are no affiliate links and no sponsored placements. Four-Leaf is our own product, and we use the same format and the same scrutiny for it as for every other tool on the list.

For broader context on what employers actually screen for in 2026, see our own research, the AI Stack Index.

Quick comparison

Prices for Four-Leaf, Aced, and Interviewing.io come from our pricing records, with Aced last verified on 16 September 2026 and Interviewing.io on 7 August 2026. Several vendors do not publish prices on a readable page, so confirm current pricing on each site before signing up.

How to choose

Three scenarios.

You can't reliably solve medium problems yet. Start with patterns. NeetCode for a free structured roadmap, then LeetCode for volume and company-tagged drilling. Add AlgoExpert if you prefer a smaller curated set with video explanations.

You can solve problems but struggle to explain them out loud. That gap is fixable with practice. Four-Leaf at $20 a month gives you conversational coding interviews with scored feedback on demand. Add a few Interviewing.io sessions before a high-stakes onsite for live-human realism.

You have a specific employer that uses HackerRank or CodeSignal. Practice on that engine to remove the surprise factor, then layer spoken practice on top so you are ready for the live rounds.

Whatever you pick, the tool only matters if you practice the part you are actually weak on. It is easy to over-index on problem volume and under-index on speaking, then wonder why a solvable problem fell apart in the room. Diagnose the real gap, pick the tool that trains it, and put in the reps.

Related reading

• Best mock interview platforms in 2026, 8 compared by role covers spoken practice across software, PM, and data roles.
• Best AI interview prep tools in 2026, 10 compared covers the broader interview prep field beyond coding.
• How to prepare for your first technical interview with no experience covers exactly how to start when you have no track record to lean on.
• Try Four-Leaf's voice mock interviews directly to rehearse a coding round out loud with scored feedback.