VoltageGPU vs CoCounsel (Thomson Reuters)

The honest framing of this comparison is that CoCounsel and VoltageGPU are not the same product, and the buyer who needs both will end up paying for both. CoCounsel's structural value is Westlaw integration, caselaw search across the dominant US legal research corpus, citator analysis, KeyCite, and the depth of Thomson Reuters' editorial layer that took the company decades to build. That is a real moat. Firms that pay $428 per seat per month for Westlaw Precision with CoCounsel are not paying for the AI in isolation; they are paying for the AI grounded against the caselaw library they were already paying for, in a workflow that links a generated brief back to the cited authority. The AI layer on top is GPT-4-class behavior with legal-specific prompts and Thomson Reuters' own models layered in. Useful, but not the moat.

VoltageGPU does not attempt to replace the caselaw moat. We do not maintain a US caselaw corpus, we do not ship a citator, and we do not pretend that an open-weight model alone is a substitute for Westlaw's editorial coverage of US state and federal jurisprudence. If your firm's daily work is "find me the cases that say X in the Second Circuit", CoCounsel with the Westlaw Precision bundle is the right tool and there is no architectural reason to use anything else.

What we do replace is the AI layer on top, the part where a lawyer uploads a 200-page Share Purchase Agreement, asks for a redline against a previous version, asks for the indemnity caps and the change-of-control triggers extracted into a table, asks for a clause-by-clause comparison against a precedent, or asks for a due-diligence summary across thirty files in a data room. That work is document-centric, not caselaw-centric. The value comes from the AI reading the document well, not from the AI cross-referencing Westlaw. For that work, the same workflow runs on VoltageGPU agents under a French controller, with the model in an Intel TDX enclave at our inference provider, at $349/mo for a team of three or $1,199/mo for ten seats with nine agents, a fraction of the per-seat CoCounsel price. Our servers see the documents in clear while the agent works on them. The two products are complementary, not substitutable: keep Westlaw for case research, use VoltageGPU agents for the documents.

Casetext was a $220/seat/month legal research and AI platform when Thomson Reuters acquired it in April 2023 for $650 million. The original CoCounsel product, then called Casetext CoCounsel, was an AI assistant built on OpenAI GPT-4 that did contract review, deposition prep, document summarization, and legal research, with Casetext's own caselaw search included in the base subscription. For a solo or small-firm buyer, that was a single line item with caselaw and AI bundled together at a defensible price.

In April 2025 Thomson Reuters retired the Casetext brand and rebuilt the product as CoCounsel inside the Thomson Reuters platform. Existing Casetext customers were migrated to one of two new tiers: CoCounsel Core at $225 per seat per month, which is AI-only with no caselaw search included; or Westlaw Precision with CoCounsel at $428 per seat per month, which adds the Westlaw caselaw corpus back into the bundle. For a buyer who was paying around $220/seat for Casetext with caselaw included, the practical migration cost was 2–3× depending on which path they chose, because the AI line item and the caselaw line item were separated and the bundled version got upsold against the standard Westlaw subscription.

This is a useful data point for thinking about lock-in. Legal AI built on top of a research platform is two coupled capabilities sold as one workflow, and the buyer ends up paying twice when the vendor decides to unbundle. The architectural alternative is to keep the caselaw subscription independent, Westlaw, Lexis, or whichever your firm already runs, and to source the AI layer from a provider whose entire product is the AI layer. That is what VoltageGPU's agent product is. We do not own a caselaw corpus, we do not have any reason to bundle one against you, and our pricing has been $349 for a small team and $1,199 for a mid-market team since the agents product launched. No forced migration, no bundle re-engineering, no AI premium layered on top of a research platform.

Where CoCounsel genuinely wins: Westlaw integration is the dominant US caselaw research surface and there is no like-for-like open-source replacement; Thomson Reuters has a procurement track record at AmLaw 100 firms that is hard to dislodge for a firm with an existing TR contract; Practical Law is a proprietary how-to content library with depth across practice areas that no AI-only vendor matches; litigation analytics (judge analytics, motion outcome prediction, brief analytics across docketed cases) are surfaces TR has built over years and shipped as part of the bundle. For a firm whose work is primarily US litigation, primarily caselaw-driven, and primarily on a TR enterprise agreement already, the question is which Thomson Reuters tier to buy, not whether to switch to a non-TR product.

Where CoCounsel does not win: the AI layer itself, taken in isolation, is GPT-4-class behavior wrapped in legal-specific prompts and grounded against the Westlaw corpus when the bundle is purchased. For document-centric workflows, contract review, due diligence across a data room, drafting, summarization, compliance checks against an internal policy library, the AI quality is the relevant variable and the caselaw grounding is not in the loop. For that workload class the per-seat price is $225 (Core) or $428 (Westlaw bundle) per month for AI that runs on OpenAI and Thomson Reuters infrastructure with no Intel TDX, no GPU TEE and no hardware attestation. On that exact workload, VoltageGPU's Professional tier ships nine agents, their model in TDX, at $1,199 per month flat for ten seats, which is $120 per seat per month. The math is one-sided when the work is document review and the caselaw grounding is not the value.

The honest decision rule is workload-driven. If the work is "find the relevant cases and write the brief grounded in them", CoCounsel with the Westlaw bundle is the right tool and the $428 is a defensible line item. If the work is "review this contract, extract the indemnity caps, redline against precedent, summarize the data room", the AI is doing the value-creating step alone and the cheapest place to run that AI is in an open-weight model, and a safer place is one where the model runs inside an Intel TDX enclave whose instances you can attest. Most large law firms have both kinds of work. Most large law firms should have both kinds of tools.