Buyer's guide
Best patent search software in 2026
By Mahish Guru, Co-founder and CEO, PatentAssist.ai
Last updated
How we compared: we read each provider's own website, help pages and pricing pages on October 26, 2026 and list only what they state there. Coverage figures are the providers' own, and prices are as published on that date. Disclosure: PatentAssist makes one of the products compared.
The honest starting point: the free official databases are excellent. Espacenet, Google Patents and the USPTO's Patent Public Search cover the patent documents most prior art searches need, and examiners search the same literature. Paid tools earn their price with AI ranking, curated family data, analytics and time saved. This guide compares eleven tools on coverage, AI search, price model and the job each does best.
Quick answer
- Free, everyday: Google Patents for speed and full text, Espacenet for worldwide families and CPC, USPTO Patent Public Search for authoritative US text.
- Free natural-language search: PQAI, PatentAssist search, and The Lens (beta, signed-in users).
- Professional platforms: IPRally and Amplified for AI search, Orbit Intelligence and Derwent for curated data and Boolean depth, PatSnap for search plus R&D analytics.
Patent search tools compared
| Tool | Coverage | AI or semantic search | Price model (as of October 26, 2026) | Best for |
|---|---|---|---|---|
| Google Patents | 120M+ publications from 100+ offices; full text for many offices, older documents often abstract-only; optional Google Scholar literature | Keyword search over full text; Prior Art Finder suggests terms from a pasted block of text | Free | Fast first-pass full-text searching |
| Espacenet (EPO) | 150M+ patent documents worldwide, 1782 to today, with machine translation | Keyword, field and classification searching; no AI search described | Free | Worldwide families, CPC classification searching and European documents |
| USPTO Patent Public Search | US grants in full text from 1971 (limited data back to 1790); pre-grant publications from March 2001; no foreign databases | No: the USPTO says it does not use semantic searching; results ranked by keyword relevance | Free; USPTO account sign-in required from November 7, 2026 | Authoritative US full text with examiner-style query syntax |
| The Lens | Patents from 100+ countries plus 200M+ scholarly records, linked | AI natural-language search (beta) for signed-in users, limited to 10 searches a day | Free for non-commercial use; commercial individual licence $1,000/year; institutional plans on request | Searching patents and scholarly literature together, especially for research |
| PQAI | 100M+ patents; lists USPTO, EPO and DOAJ as data sources | Yes: natural-language search | Free (up to 20 results per query); PQAI+ $20/month or $216/year; API from $20/month | Inventors and startups wanting a free natural-language first pass |
| PatSnap | 215M+ patents from 174 jurisdictions, plus 260M+ scientific papers | Yes: AI agents (Eureka) that answer questions with citations | Eureka Basic free with daily limits; Pro from $100/month; Analytics and enterprise on request; 14-day trial | R&D and IP teams that want search, analytics and AI in one platform |
| Orbit Intelligence (Questel) | 100M+ patents, 17M designs and 150M non-patent documents; full text from 59 offices | Sophia assistant turns a natural-language question into a Boolean query | Paid; pricing on request | Professional searchers who want curated family data and Boolean control |
| Derwent (Clarivate) | DWPI: 120M+ patents in 62M+ invention families, with rewritten abstracts | Yes: AI search using a language model trained on DWPI | Commercial subscription; contact Clarivate | Teams that rely on DWPI's editorially rewritten abstracts |
| IPRally | 130M+ patents from 58 jurisdictions, full text | Yes: AI search from any input, without keyword limits | Paid; annual per-seat plans, price on request | Professional searchers who want AI search from a full disclosure |
| Amplified | 140M+ patents, updated weekly | Yes: AI, semantic and traditional search, with two ranking modes | From $500/month, paid annually; team and enterprise on request | Teams that want AI and Boolean search together with shared workspaces |
| PatentAssist search | 20M+ USPTO, EPO and IP India documents, with full text and drawings | Yes: AI agentic search from a plain-language description, plus field search | Free, no sign-up; patentability reports in the drafting app's plans | A free AI first pass across US, European and Indian records, then drafting |
PatentAssist publishes this guide and runs one of the tools listed. Coverage figures are each provider's own, checked October 26, 2026, and are not directly comparable: some count publications, some patents, some families. Prices are in US dollars and listed only where the provider publishes them.
The 11 tools, reviewed
1. Google Patents
Best for: Fast first-pass full-text searching. Price: Free.
Google Patents is where most searches start, and for good reason: it is fast, free, and searches title, abstract, claims and description together. Paste a paragraph from a disclosure and its Prior Art Finder pulls out search terms; tick "Include non-patent literature" to add Google Scholar results. Google's own help page says it cannot guarantee complete coverage and that older documents often have only an abstract, so treat it as a first pass, not the final word.
2. Espacenet (EPO)
Best for: Worldwide families, CPC classification searching and European documents. Price: Free.
Espacenet is the EPO's free database, with more than 150 million documents from around the world going back to 1782. Its strength is structure: patent families, CPC classification and machine translation of foreign documents, which makes it the natural place to work through a CPC group or check what a family looks like across offices. The EPO describes it as accessible to beginners and experts, and points bulk users to its Open Patent Services API instead.
3. USPTO Patent Public Search
Best for: Authoritative US full text with examiner-style query syntax. Price: Free; USPTO account sign-in required from November 7, 2026.
Patent Public Search is the USPTO's own tool, built on the search system examiners use. For US documents it is the authoritative source: full text of most patents issued since 1971 and pre-grant publications since March 2001. It has no foreign collections and, in the USPTO's words, does not use semantic searching, so it rewards precise Boolean and proximity queries. From November 7, 2026, the USPTO requires a USPTO account to sign in.
4. The Lens
Best for: Searching patents and scholarly literature together, especially for research. Price: Free for non-commercial use; commercial individual licence $1,000/year; institutional plans on request.
The Lens links patents to scholarly literature, with more than 200 million scholarly records next to patents from over 100 countries, which makes it unusually good for non-patent prior art. In October 2026 it added an AI natural-language search for signed-in users, in beta and capped at ten searches a day. Anonymous and personal non-commercial use is free; commercial use needs a licence, published at $1,000 a year for an individual.
5. PQAI
Best for: Inventors and startups wanting a free natural-language first pass. Price: Free (up to 20 results per query); PQAI+ $20/month or $216/year; API from $20/month.
PQAI is a natural-language patent search aimed at inventors, researchers and start-ups: describe the idea and it returns the closest documents. The free plan shows up to 20 results per query, which is enough for a quick sense check; PQAI+ at $20 a month raises that to 500 with excerpts and export. A separate API is priced from $20 a month.
6. PatSnap
Best for: R&D and IP teams that want search, analytics and AI in one platform. Price: Eureka Basic free with daily limits; Pro from $100/month; Analytics and enterprise on request; 14-day trial.
PatSnap is a large commercial platform with 215 million-plus patents from 174 jurisdictions and 260 million-plus papers. Its Eureka products add AI agents that answer plain-language questions with citations, with a limited free tier and Pro plans from $100 a month; the Analytics platform and enterprise tiers are quoted. A 14-day trial needs no card.
7. Orbit Intelligence (Questel)
Best for: Professional searchers who want curated family data and Boolean control. Price: Paid; pricing on request.
Orbit Intelligence is Questel's professional search platform, built on its FamPat family database: more than 100 million patents, 17 million designs and 150 million non-patent documents, with full text from 59 offices. Its AI assistant, Sophia, writes a Boolean query from a natural-language question that you can then adjust, which suits searchers who want AI help without giving up control of the query. Pricing is through Questel.
8. Derwent (Clarivate)
Best for: Teams that rely on DWPI's editorially rewritten abstracts. Price: Commercial subscription; contact Clarivate.
Derwent's distinguishing feature is the Derwent World Patents Index, where editors rewrite abstracts in plain technical English and group documents into invention families: Clarivate cites more than 120 million patents in over 62 million families. In December 2024 Clarivate added AI search that reads input text with a language model trained on DWPI. It is a commercial subscription sold by Clarivate.
9. IPRally
Best for: Professional searchers who want AI search from a full disclosure. Price: Paid; annual per-seat plans, price on request.
IPRally's AI search takes any input, from a claim to a whole disclosure, and returns ranked results without you writing a keyword query. It covers more than 130 million patents from 58 jurisdictions in full text. Plans are single user, team (per seat, annual) and enterprise, all priced on request; trials are offered at IPRally's discretion for formal evaluations.
10. Amplified
Best for: Teams that want AI and Boolean search together with shared workspaces. Price: From $500/month, paid annually; team and enterprise on request.
Amplified combines AI and semantic search with traditional search over more than 140 million patents, updated weekly, and offers two ranking modes. It publishes a starting price of $500 a month paid annually, with team and enterprise plans by quote.
11. PatentAssist search
Best for: A free AI first pass across US, European and Indian records, then drafting. Price: Free, no sign-up; patentability reports in the drafting app's plans.
PatentAssist search covers 20 million-plus USPTO, EPO and IP India documents. Describe the invention in plain language and the AI agentic search runs the queries, or use classic field search by applicant, inventor, classification or number. It is free and needs no account. It is narrower than the worldwide databases above, so for a full search add Espacenet or a commercial tool; inside the PatentAssist drafting app, the same search feeds patentability reports and the claims, with a 7-day free trial.
How to choose, and how to combine them
Match the tool to the question. A quick novelty check before an inventor meeting is a different job from a freedom-to-operate search before a product launch. For the first, a free AI search plus Google Patents is usually enough. For the second, you want worldwide coverage, legal status, family data and a search record you can defend, which is where Espacenet's structure or a professional platform pays off.
Use AI search to find the words, then search properly. Natural-language search is good at surfacing documents that describe the same idea in different vocabulary. Read the top results, note the terms and CPC groups they use, then run Boolean and classification queries over those areas in Espacenet or Patent Public Search. That gives you both recall and a record of what you searched.
Check the coverage you actually need. Patent Public Search has no foreign documents. Coverage numbers on vendor sites count different things (publications, patents, families), so compare them on the offices and years that matter to your field, not on the headline figure.
Do not forget non-patent literature. In software, materials and life sciences the closest prior art is often a paper. The Lens links patents to scholarly records, Google Patents can add Google Scholar results, and PatSnap and Orbit index papers alongside patents.
Think about confidentiality. Typing an unfiled invention into any online tool sends it to a third party. Read the tool's terms and data policy first, and for sensitive cases search with features rather than the full disclosure. How PatentAssist handles your data is on its security page.
Where PatentAssist search fits
PatentAssist search is a free AI first pass over 20 million-plus US, European and Indian documents, with no account needed. It is not a worldwide database, so use it next to Espacenet or Google Patents rather than instead of them. Its main advantage comes when you draft: in the PatentAssist app the same search feeds patentability reports and the claims, so the draft is shaped around what you found.
Search one office directly: USPTO, EPO, IP India. Comparing drafting tools too? Read the best AI patent drafting tools or the alternatives guides.
Patent search software: frequently asked questions
What is the best free patent search tool?
For most people, use two: Google Patents for fast full-text searching and families, and Espacenet for worldwide coverage, CPC classification and machine translation. For US documents, add USPTO Patent Public Search. The Lens is free for non-commercial use and is strong on scholarly literature, and PQAI and PatentAssist search offer free natural-language search.
Are free patent databases good enough for a prior art search?
Often, yes. Espacenet, Google Patents and USPTO Patent Public Search cover the documents most searches need, and examiners use the same patent literature. Paid tools save time with curated families, analytics and AI ranking, and add collections such as DWPI abstracts. For a freedom-to-operate or invalidity search with money at stake, a professional searcher's time matters more than the tool.
Which patent search tools use AI or semantic search?
PQAI, IPRally, Amplified, PatSnap, Derwent, PatentAssist search and The Lens (in beta) describe AI or natural-language search. Orbit Intelligence's Sophia writes a Boolean query from a question. The USPTO says Patent Public Search does not use semantic searching, and Google Patents' Prior Art Finder suggests keywords rather than running a semantic search.
Do I need an account for USPTO Patent Public Search?
From November 7, 2026, the USPTO requires users to sign in with a USPTO account to use Patent Public Search. Espacenet, Google Patents and PatentAssist search can be used without an account.
Should I use AI search or Boolean search?
Both. AI search is good at finding documents that describe the same idea in different words, from a paragraph of disclosure. Boolean and classification searching gives you control and a record you can repeat and explain. A common pattern is an AI search to find the right vocabulary and CPC groups, then Boolean and classification queries to search those areas thoroughly.
How much does commercial patent search software cost?
Of the paid tools here, PQAI+ is $20 a month, PatSnap's Eureka Pro starts at $100 a month, Amplified starts at $500 a month paid annually and The Lens charges $1,000 a year for individual commercial use. IPRally, Orbit Intelligence and Derwent quote on request.
General information about search tools, not legal advice. For a search you will rely on, such as freedom to operate, work with a registered patent attorney or agent or a professional searcher.