Mike Holt accuracy test (review 8)

Why accuracy matters more than features

Mike Holt has been the gold standard for code training for decades. His books, videos, and seminars built an entire generation of electricians. When I started testing Ask BONBON against other code references, Mike Holt's digital resources were the benchmark. If an app cannot match Holt for accuracy, it has no business being on your phone.

This review is not a takedown. Holt's material is excellent for learning. But learning resources and field references serve different jobs. On a jobsite with the inspector waiting, you need the answer, not a lecture. I spent two months running parallel lookups on both, and here is what I found.

The test methodology

I built a list of 50 code questions pulled from real jobs I worked between January and March 2026. Kitchen remodels, a small commercial tenant fitout, a panel swap, two EV charger installs, and a handful of service upgrades. Every question had a definitive NEC answer I could verify against the 2023 code book.

For each question, I timed the lookup on both platforms and scored the answer on three criteria: correct article cited, correct interpretation, and whether the answer matched what my AHJ would accept. I ran the tests on a Pixel 8 with spotty service at one commercial site, which mattered more than I expected.

• 50 field questions pulled from actual work orders
• Graded on citation accuracy, interpretation, and AHJ alignment
• Timed from question entered to usable answer on screen
• Tested on LTE, WiFi, and offline where possible

Where Mike Holt wins

On deep code theory, Holt is untouchable. Ask about the reasoning behind NEC 250.32(B) for separate structures, and Holt's material walks you through grounding versus bonding with diagrams that actually make sense. The illustrated code book is worth every dollar if you are studying for a license exam or teaching an apprentice.

Holt also nails the tricky interpretation questions. I asked about feeder tap rules under NEC 240.21(B) for a 25 foot tap inside a building, and the Holt explanation covered the ampacity requirements, overcurrent protection placement, and physical protection rules in one clean pass. BONBON got the answer right too, but Holt's context was richer.

Tip from the field: if you are prepping for a master's exam or need to argue an interpretation with an inspector, print the relevant Holt pages before you leave the truck. The diagrams carry weight in a plan review.

Where Ask BONBON wins

Speed. On 50 lookups, BONBON averaged 14 seconds from question to answer. Holt's digital material averaged 2 minutes 40 seconds, mostly because you are navigating a book interface or watching a video segment to find the answer. When I am on a ladder with a hot panel below me, two and a half minutes is not acceptable.

Offline access was the bigger gap. At the commercial fitout, the basement mechanical room had zero signal. BONBON's cached code library answered a question about NEC 408.4(A) panel directory requirements in seconds. Holt's platform needed a connection I did not have, so I walked upstairs, checked, and walked back. Three trips like that adds 20 minutes to a job.

1. NEC 210.8(A) GFCI locations in dwellings, BONBON 11 sec, Holt 2 min 15 sec
2. NEC 310.16 ampacity for 3/0 copper THWN, BONBON 8 sec, Holt 1 min 50 sec
3. NEC 680.26 equipotential bonding for pools, BONBON 22 sec, Holt 3 min 10 sec
4. NEC 422.16(B)(2) dishwasher cord and plug rules, BONBON 9 sec, Holt 2 min 40 sec

Accuracy head to head

On citation accuracy, both tools hit 50 out of 50. Neither cited a wrong article. That surprised me, because I had seen other apps confidently point at the wrong section of the code. BONBON and Holt both respect the source material.

On interpretation, Holt scored 50 out of 50 and BONBON scored 48 out of 50. The two BONBON misses were both on multi-family dwelling feeder calculations under NEC 220.84, where the answer was technically correct but missed a nuance about optional calculation qualifications. I reported both and they were corrected within a week. Holt has had decades to refine its material, so matching it 96 percent out of the gate is respectable.

The verdict from the truck

Mike Holt is a teacher. Ask BONBON is a reference. You need both, but you need them at different moments. When I am studying on the couch Sunday night, Holt wins. When I am kneeling in a crawlspace at 3 PM trying to finish a rough inspection, BONBON wins because it answers before the inspector loses patience.

The honest take: do not replace your Holt library. Keep the illustrated code book, keep the exam prep material. But stop pretending a learning platform is a field tool. Get a dedicated reference app for the jobsite, and let Holt do what Holt does best.

Tip from the field: the right test for any code app is not "can it answer this question," it is "can it answer this question in under 30 seconds with no signal while I am holding a multimeter." That filter kills 90 percent of the options.