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Home › Compare › Lexis+ AI vs Westlaw AI

Lexis+ AI vs Westlaw AI: what lawyers say.

Short answer. Lexis+ AI has net sentiment −14 on 294 public lawyer voices and Westlaw AI has +6 on 268, as of . Westlaw AI is ahead on this record: the two 90% bands do not overlap. Net is like minus dislike as a share of voices.

Lexis+ AI

−14

net · band −23 to −6

294 voices Medium

vs
Westlaw AI

+6

net · band −3 to +14

268 voices Medium

Westlaw AI ahead on this record: the two 90% bands do not overlap.

294 voices on Lexis+ AI and 268 on Westlaw AI, all public posts by lawyers and people who work with them, since 2023. This is how they describe using each tool, not a test of the tools. Lexis+ AI is a legal research platform by LexisNexis; Westlaw AI is a legal research platform by Thomson Reuters.

Side by side

Rates and bands, not raw totals.

Lexis+ AIWestlaw AI
Voices on record294268
Like · mixed · dislike94 · 46 · 136106 · 59 · 91
Net like minus dislike, % of voices−14 90% band −23 to −6+6 90% band −3 to +14
ConfidenceMediumMedium
Per 100 voices: like · dislike · name hallucinations32 · 46 · 1140 · 34 · 12
Latest voice

Westlaw AI has the higher net (+6 against −14) and the two 90% bands do not overlap. That describes who posts and how they feel, not which product is better. Difference in net: −20 points (Lexis+ AI minus Westlaw AI).

By task

What they were doing when they posted.

TaskLexis+ AIWestlaw AI
Legal research184 voices · net −10210 voices · net +13
Drafting18 voices · net −113 voices, too few for a net
Citation checking17 voices · net −4711 voices · net −45
Summarization10 voices · net −4011 voices · net −9
General use61 voices · net −1031 voices · net −29

Net here is plain like minus dislike as a share of that task’s voices, with no band: a task needs 5+ voices on a side to show one. Tasks with fewer on both sides are left out. A voice has one task, set by our classifier.

What they complain about and value

Lexis+ AI · complaints

  • Accuracy 132
  • Hallucination 32
  • Price 26

Lexis+ AI · what they value

  • Time saved 47
  • Accuracy 25
  • Data coverage 23

Westlaw AI · complaints

  • Accuracy 112
  • Hallucination 32
  • Price 22

Westlaw AI · what they value

  • Time saved 61
  • Data coverage 30
  • Accuracy 29

Counts are voices that name that complaint or value (top three per tool). A voice can name one of each. Not a comparison of raw totals: the bigger side has more posts of every kind.

In their own words

Each quote is a verbatim span of a counted voice, with its date and a link to the original.

On Lexis+ AI · verbatim

r/LawFirm
“If you’re ok with those then it’s silly to be concerned with lexis.”

in “Protege with client data” · 3 voices

ValuesGeneral useUnverified voice
Original thread Share
2 more voices in this thread
  • r/LawFirm · Sep 21, 2026Lexis+ AINeutral“The firm rule you already have is the right floor: written no-train and confidential handling before any client data goes in. Protege Enterprise can meet that bar on paper.”open
  • r/LawFirm · Sep 21, 2026Lexis+ AINeutral“If your practice group cant name those four things, Protege is still a trust exercise.”open
r/Lawyertalk
“My firm has Lexis Protege AI which I use mostly for AI-assisted legal research and simple motion drafting, but I feel that I'm probably missing out on its full potential.”

in “Lexis Peotege”

NeutralResearchSays: works at a law firm
Original thread Share
Hacker News
“It didn't feel drastically different from using ChatGPT with the ability to search the web [...]”

in “AI outperforms law professors in Stanford Law study” · 9 voices

MixedResearchUnverified voice
Original thread Share
8 more voices in this thread
  • Hacker News · Jun 3, 2026CriticizesLLM-drafted motions look good and usually pass unnoticed but are ethically dubious and hard for a human to catch, and reviewers grow lazier as the models improve. (summary, not a quote)open
  • Hacker News · Jun 3, 2026MixedAI often outperforms knowledge workers, but only with the right questions and correction, and unchecked errors could be catastrophic in high-risk fields like legal work. (summary, not a quote)open
  • Hacker News · Jun 3, 2026Lexis+ AIValues“This is where AI offerings from Thomson or Lexis could shine, especially in jurisdictions where case law is not freely available online.”open
  • Hacker News · Jun 3, 2026MixedAI chatbots can save some work, but their knowledge cutoff means they miss recent case law, so professionals relying on them risk personal liability and may have to redo the work. (summary, not a quote)open
  • Hacker News · Jun 3, 2026ChatGPTMixed“They are unbelievable at finding niche cases you would never have found on your own.”open
  • Hacker News · Jun 3, 2026GeminiNeutral“NotebookLM was considered slightly better than 2.5 Pro by the evaluators.”open
  • Hacker News · Jun 3, 2026NeutralUses a coding agent to do initial legal research and drafting, pulls the full text of cited laws, then has Gemini look for issues and criticize the draft. (summary, not a quote)open
  • Hacker News · Jun 3, 2026GeminiCriticizesAsked Gemini about personal conflicts; found it too conservative and shallow, so handles serious matters himself, using AI only for templated text. (summary, not a quote)open

On Westlaw AI · verbatim

r/biglaw
“I use co counsel for litigation and i find it is much more accurate for litigation research than claude, chatgpt, or gemini.”

in “Harvey / Legora are awful.” · 38 voices

ValuesAccuracyUnverified voice
Original thread Share
37 more voices in this thread
  • r/biglaw · Oct 19, 2026CriticizesLegal SaaS platforms like Harvey and Legora are just wrappers around LLMs, and the author's firm built its own in-house platform and sees their valuations as unjustified. (summary, not a quote)open
  • r/biglaw · Oct 18, 2026HarveyValues“Boomer here, but I think Harvey is incredible.”open
  • r/biglaw · Oct 18, 2026HarveyValues“When you know what you are doing and what you want, Harvey is great IMO.”open
  • r/biglaw · Oct 17, 2026CoCounselNeutral“CoCounsel allows you to build workflows and combine with other sources too, though.”open
  • r/biglaw · Oct 17, 2026HarveyValues“The US caselaw search is better because you can combine it with other sources so you can have it look through a set of litigation documents and run caselaw research to help figure out their significance at the same time.”open
  • r/biglaw · Oct 17, 2026ClaudeValues“To be very clear, in my experience having these systems finely tuned to your individual work vs the level of tuning you can get out of harvey/cocounsel/co-pilot can represent 2-3x productivity increases.”open
  • r/biglaw · Oct 17, 2026HarveyValues“Harvey vault is amazing for working with discovery productions.”open
  • r/biglaw · Oct 16, 2026HarveyNeutral“Harvey also has a US Caselaw database where whichever model you pick will directly search for cases in the database.”open
  • r/biglaw · Oct 16, 2026CriticizesSays lawyers will not use raw coding or chat tools and need a wrapper around the model to make it usable. (summary, not a quote)open
  • r/biglaw · Oct 16, 2026HarveyNeutral“Harvey can be used with Astra 6 or Fable, your firm just has to agree to API pricing.”open
  • r/biglaw · Oct 16, 2026HarveyNeutral“Harvey uses the Chat GPT and Claude models and you can actually pick which model.”open
  • r/biglaw · Oct 16, 2026ChatGPTValues“What pisses me off is that our clients ARE using Claude and ChatGPT themselves and we’re stuck using these inferior models.”open
  • r/biglaw · Oct 16, 2026HarveyNeutral“Alls I know is that I can’t keep track of all the platforms so I stick to my mans Harvey even though the other mans might be better.”open
  • r/biglaw · Oct 16, 2026HarveyNeutral“You do realize that Harvey was literally just an interface to access Claude since day 1.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“Harvey and Legora are inferior products, by magnitudes, and any firm that exclusively relies on these tools is falling behind in productivity and associate satisfaction.”open
  • r/biglaw · Oct 15, 2026ClaudeValues“If you are using Fable and you give it enough project data, it can function like your associate on that case who has a mastery of facts and super fast turnaround.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“Harvey sucks because it's just an API built on top of open-source AI models, which are way behind the models currently available through openAI or Claude.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizesYounger lawyers who grew up with general AI tools would be disadvantaged by using Harvey, while older lawyers can be forgiven for adopting it. (summary, not a quote)open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“This is basically a fine tuned version of the Kimi K3 model which they claim is better but is clearly worse”open
  • r/biglaw · Oct 15, 2026HarveyNeutral“Harvey does have its own propriety model. And yes, if you select a specific model, only the output is generated by that model, not all of the intervening tasks.”open
  • r/biglaw · Oct 15, 2026HarveyNeutral“There is no “Harvey” model. Harvey just picks one of the models based on your prompt.”open
  • r/biglaw · Oct 15, 2026HarveyMixed“I like to think of Harvey as an energetic junior, does their best, a fine starting point, but doesn’t produce a product I’d be willing to send a client without a deeeep review”open
  • r/biglaw · Oct 15, 2026HarveyValues“Harvey's been killing it for me on the transaction side with the rote drafting and title work.”open
  • r/biglaw · Oct 15, 2026CoCounselValues“I’ve been really impressed and don’t see how a tool could be much better”open
  • r/biglaw · Oct 15, 2026CoCounselValues“I’ve been really impressed and don’t see how a tool could be much better”open
  • r/biglaw · Oct 15, 2026HarveyValues“I use Harvey daily and think it’s a fantastic product (as long as you use it to supplement, not replace your work product)”open
  • r/biglaw · Oct 15, 2026CoCounselValues“I use co counsel for litigation and i find it is much more accurate for litigation research than claude, chatgpt, or gemini.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“Even when I add docs to a vault and ask for a review table, getting Harvey to actually “read” the docs is like pulling teeth.”open
  • r/biglaw · Oct 15, 2026ClaudeValues“Claude code with a syfert.com MCP (or a courtlistener MCP, or ding duff) is 500% better than Harvey and Legora.”open
  • r/biglaw · Oct 15, 2026HarveyMixed“It’s usually right but the times it isn’t it’s REALLY wrong.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“I also do not think I’m getting real Opus 5 when I select it in Harvey. And it’s hella slow.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“Harvey profits by arbitrating token costs, so they use the cheapest models they think can get away with for the bulk of response.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“They came out years later than Harvey, when firms already adopted Harvey, but yeah, firms should abandon Harveyw”open
  • r/biglaw · Oct 15, 2026CoCounselValues“My firm has Harvey and CoCounsel, and I just use CC bc it has access to Westlaw.”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“It routinely gives me genuinely “lazy” answers that fail to address what are obviously critical aspects of the issue, in a way that is not true of Fable or Astra”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“The only reason firms choose Harvey is it doesn’t use our data to train its AI due to confidentiality, or else they are trash”open
  • r/biglaw · Oct 15, 2026HarveyCriticizes“All other tasks, such as the actual research, review, etc, are handled by whatever model Harvey wants, including their own shitty “proprietary” models.”open
r/LawFirm
“These companies move too slowly and, since they are subscription based, they have an incentive to use cheap (aka bad) AI models to save on costs.”

in “Why does my mid-sized firm continuously shove our “AI tools” down my throat?” · 4 voices

CriticizesAccuracyUnverified voice
Original thread Share
3 more voices in this thread
  • r/LawFirm · Oct 15, 2026ClaudeMixed“I've found that Haiku and Sonnet do not do as good a job and correcting errors that result from them makes me waste time.”open
  • r/LawFirm · Oct 13, 2026ChatGPTValues“There are some other minor details but that research workflow has proven to be exponentially better than I could ever do and still significantly better than lexis or westlaw AI were ever able to do for me.”open
  • r/LawFirm · Oct 13, 2026CoCounselMixed“Westlaw's CoCounsel will get you in the right zip code but its descriptions of the cases it finds for me are often still incorrect and need to be verified personally.”open
Hacker News
“What legal professionals actually pay for [...] is to give the AI access to a legal database of case law.”

in “Mike: open-source legal AI” · 7 voices

ValuesData coverageUnverified voice
Original thread Share
6 more voices in this thread
  • Hacker News · May 5, 2026ChatGPTValuesPro se litigant ran two years of federal litigation on a $20 ChatGPT plan for research, drafting and discovery, and forced a settlement. (summary, not a quote)open
  • Hacker News · May 2, 2026ChatGPTCriticizes“With ChatGPT and Claude, the risk is much higher, because you're basically uploading entire documents with potentially privileged material to a third party, as part of your prompt.”open
  • Hacker News · May 2, 2026HarveyMixed“LLMs are absolutely abysmal at legal research and analysis, and every week we are seeing reports of some lawyer being called out publicly for submitting a brief to a court with hallucinated case citations.”open
  • Hacker News · May 2, 2026MixedOpen-source legal AI is better and fine for general work, but insufficient for full research without near-complete case law coverage. (summary, not a quote)open
  • Hacker News · Apr 30, 2026CriticizesLegal professional says generic LLM wrapper is no replacement for Westlaw; cannot rely on it without recourse if wrong. (summary, not a quote)open
  • Hacker News · Apr 30, 2026ValuesLawyer uses AI extensively but manually reads every cited case and checks on Westlaw it is still good law. (summary, not a quote)open

When both come up in one thread

Voices from threads where posters name Lexis+ AI and Westlaw AI. Open the thread for the whole exchange.

r/Lawyertalk
Lexis+ AI
“Protege is directly part of Lexis and still can’t be trusted.”

in “How does anyone think this is ok?” · 3 voices

CriticizesTrust, liabilityUnverified voice
Original thread Share
2 more voices in this thread
  • r/Lawyertalk · Aug 20, 2026CriticizesAI pin cites are unreliable even when the main case cite is right, and even the legal AI vendors warn users to double-check them. (summary, not a quote)open
  • r/Lawyertalk · Aug 19, 2026Westlaw AICriticizes“Running a brief through Westlaw cite check is insufficient IMO. It is just another AI platform.”open
r/Lawyertalk
Westlaw AI
“Running a brief through Westlaw cite check is insufficient IMO. It is just another AI platform.”

in “How does anyone think this is ok?” · 3 voices

CriticizesAccuracyUnverified voice
Original thread Share
2 more voices in this thread
  • r/Lawyertalk · Aug 20, 2026CriticizesAI pin cites are unreliable even when the main case cite is right, and even the legal AI vendors warn users to double-check them. (summary, not a quote)open
  • r/Lawyertalk · Aug 20, 2026Lexis+ AICriticizes“Protege is directly part of Lexis and still can’t be trusted.”open
r/Lawyertalk
Lexis+ AI
“(I am ethically opposed to AI but Protege hallucinates like crazy).”

in “Me to the Lexis rep trying to sell their AI” · 7 voices

CriticizesHallucinationUnverified voice
Original thread Share
6 more voices in this thread
  • r/Lawyertalk · Jul 4, 2026Lexis+ AIMixed“Protoge is ok. It’s basically GPT with links to town/village court level decisions.”open
  • r/Lawyertalk · Jul 3, 2026Lexis+ AICriticizes“My firm has lexis and has gone all in on the AI. I hate it.”open
  • r/Lawyertalk · Jul 3, 2026ClioValues“I have Clio’s AI, and it is the best legal search I have ever used.”open
  • r/Lawyertalk · Jul 3, 2026CoCounselValues“It's the only LLM I've used that serves it's purpose”open
  • r/Lawyertalk · Jul 2, 2026Westlaw AIValues“I'll say: Westlaw's AI is helpful for research.”open
  • r/Lawyertalk · Jul 2, 2026Lexis+ AICriticizes“Lexis sucks ass and their desparate reps know it.”open
r/Lawyertalk
Westlaw AI
“I'll say: Westlaw's AI is helpful for research.”

in “Me to the Lexis rep trying to sell their AI” · 7 voices

ValuesData coverageUnverified voice
Original thread Share
6 more voices in this thread
  • r/Lawyertalk · Jul 5, 2026Lexis+ AICriticizes“(I am ethically opposed to AI but Protege hallucinates like crazy).”open
  • r/Lawyertalk · Jul 4, 2026Lexis+ AIMixed“Protoge is ok. It’s basically GPT with links to town/village court level decisions.”open
  • r/Lawyertalk · Jul 3, 2026Lexis+ AICriticizes“My firm has lexis and has gone all in on the AI. I hate it.”open
  • r/Lawyertalk · Jul 3, 2026ClioValues“I have Clio’s AI, and it is the best legal search I have ever used.”open
  • r/Lawyertalk · Jul 3, 2026CoCounselValues“It's the only LLM I've used that serves it's purpose”open
  • r/Lawyertalk · Jul 2, 2026Lexis+ AICriticizes“Lexis sucks ass and their desparate reps know it.”open

Short answers

From the same record as the tables above.

Lexis+ AI vs Westlaw AI for lawyers: what do lawyers say?

Lexis+ AI has net sentiment −14 on 294 public lawyer voices and Westlaw AI has +6 on 268, as of . Westlaw AI is ahead on this record: the two 90% bands do not overlap. Net is like minus dislike as a share of voices.

How many lawyers have posted about Lexis+ AI and Westlaw AI?

We count 294 public voices on Lexis+ AI and 268 on Westlaw AI, posted since 2023 by lawyers and people who work with them, as of . Each voice is one post or comment that names the tool.

Do lawyers feel better about Lexis+ AI or Westlaw AI?

Net sentiment (like minus dislike, as a share of voices) is −14 for Lexis+ AI, 90% band −23 to −6, and +6 for Westlaw AI, 90% band −3 to +14. Westlaw AI has the higher net (+6 against −14) and the two 90% bands do not overlap. That describes who posts and how they feel, not which product is better.

What do lawyers use Lexis+ AI and Westlaw AI for?

The task named most often on Lexis+ AI is legal research (184 of 294 voices); on Westlaw AI it is legal research (210 of 268 voices). A voice has one task, set by our classifier.

Task reports with both: Legal research report · Summarization report · Citation checking report