Lexis+ AI vs Spellbook:Which is more popular?
In September 2026, Spellbook had more branded searches than Lexis+ AI among AI legal assistants worldwide. Spellbook had about 22,200 branded searches, while Lexis+ AI had 16,500. Spellbook made up 8.7% of all AI legal assistant searches we track, and Lexis+ AI accounted for 6.5%. When we asked ChatGPT and Google AI Overviews about AI legal assistants, Lexis+ AI appeared in all five answers and Spellbook in one. Lexis+ AI was mentioned before Spellbook in every answer.
Who do people search for more?
Spellbook, about 35% more searches than Lexis+ AI
Who does AI mention more?
Lexis+ AI, mentioned in every answer we collected
Who does AI recommend more?
Lexis+ AI, named ahead of Spellbook in every answer
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Top AI legal assistants in ChatGPT and Google AI Overviews
In three ChatGPT questions and two Google AI Overviews, Lexis+ AI appeared in all five answers. Spellbook was mentioned in one out of five: in one of the three ChatGPT answers, but not in either of the two Google AI Overviews. Lexis+ AI was listed before Spellbook in every answer.
Most recommended by AI
Brands get a higher ranking if they are mentioned earlier in the answers.
Mentioned by AI
Each dot is one answer, filled in when that answer mentions the brand.
CoCounsel5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers- Lexis+ AI5 of 5Named in 3 of 3 ChatGPT answersNamed in 2 of 2 Google answers
Harvey4 of 5Named in 3 of 3 ChatGPT answersNamed in 1 of 2 Google answers
LegalOn1 of 5Named in 1 of 3 ChatGPT answersNamed in 0 of 2 Google answers- Spellbook1 of 5Named in 1 of 3 ChatGPT answersNamed in 0 of 2 Google answers
DoNotPay0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
Robin AI0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
See every answer about AI legal assistants
5 answers
Asked ChatGPT
“Which AI legal assistant should I use?”
Asked ChatGPT
“What are the best AI legal assistants?”
Asked ChatGPT
“What's the best AI legal assistant for legal research?”
Searched Google, AI Overview
“ai legal assistant”
Searched Google, AI Overview
“legal research ai”
Brands are shown in the order each answer named them. The survey took place in the United States on October 20, 2026.
Is Lexis+ AI or Spellbook more popular in search?
This chart shows how often people search Google for Lexis+ AI and Spellbook by name. Each line represents a brand's share of searches for all seven AI legal assistants we track, month by month, from English-language searches worldwide.
Share of searches by month for Spellbook, Lexis+ AI. The figures are in the table below the chart.
View monthly share of searches table
| Month | Harvey | LegalOn | Spellbook | CoCounsel | Lexis+ AI | DoNotPay | Robin AI |
|---|---|---|---|---|---|---|---|
| Oct 2025 | 34.9% | 28.5% | 10.5% | 6% | 9.9% | 3.8% | 6.5% |
| Nov 2025 | 33.8% | 27.7% | 10.1% | 7.3% | 9.3% | 4.5% | 7.3% |
| Dec 2025 | 36.5% | 29.9% | 10.9% | 6.5% | 6.9% | 4% | 5.3% |
| Jan 2026 | 32.9% | 32.9% | 12.1% | 7.1% | 7.6% | 3.6% | 3.9% |
| Feb 2026 | 42.8% | 23.4% | 10.5% | 7.6% | 8.1% | 4.7% | 2.8% |
| Mar 2026 | 43.6% | 24% | 10.7% | 7.6% | 8.6% | 3.2% | 2.3% |
| Apr 2026 | 47.3% | 21.3% | 9.6% | 6.8% | 8.3% | 4.3% | 2.5% |
| May 2026 | 47.7% | 21.5% | 9.6% | 7.2% | 7.2% | 4.3% | 2.5% |
| Jun 2026 | 48.9% | 22% | 8% | 7.2% | 7.8% | 3.6% | 2.5% |
| Jul 2026 | 49.6% | 22.3% | 8.2% | 7.3% | 6.9% | 3.7% | 2.1% |
| Aug 2026 | 49.7% | 22.4% | 8.2% | 7.4% | 6.9% | 3.7% | 1.7% |
| Sep 2026 | 52.8% | 19.4% | 8.7% | 7.7% | 6.5% | 3.2% | 1.8% |
How has the Lexis+ AI and Spellbook comparison changed over the last 12 months?
3 findings
- Spellbook was ahead of Lexis+ AI in every measured month of the 12 months ending September 2026.
- Across the 12 months ending September 2026, Lexis+ AI’s share of searches among AI legal assistants worldwide moved from 9.9% to 6.5%, and its estimated monthly branded searches moved from 21K to 16.5K.
- Across the 12 months ending September 2026, Spellbook’s share of searches among AI legal assistants worldwide moved from 10.5% to 8.7%, and its estimated monthly branded searches held steady at 22.2K.
How did search popularity change for AI legal assistants worldwide in September 2026?
2 changes
In September 2026, Spellbook gained share of searches among AI legal assistants worldwide, from 8.2% to 8.7%.
Estimated monthly branded searches for Lexis+ AI worldwide fell 21.4% over 12 measured months, from 21K to 16.5K in September 2026.
How are branded searches counted?
3 search terms
Brandwave collects information about searches that people make online using Lexis+ AI’s and Spellbook’s names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.
Other head-to-heads among AI legal assistants
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