How to use USPTO Patent Public Search

Getting in: account and browser

Open the Patent Public Search page on uspto.gov and choose Basic Search or Advanced Search. The USPTO has announced that from November 7, 2026, Patent Public Search will require users to sign in with a USPTO account, so create one at MyUSPTO before you need it. If you already file through Patent Center, the same account works.

Two practical limits from the USPTO's FAQ: the tool is built for Chromium-based browsers (Chrome, Edge), and the Advanced Search interface does not support phone or tablet screens. Basic Search does. The workspace times out after 30 minutes of inactivity, with a warning two minutes before.

Basic Search vs Advanced Search

Basic Search has two things. Quick Lookup takes a patent or publication number. Below it are two query boxes, each with a field drop-down, joined by AND, OR or NOT. Leave the field on "Everything" and it searches all fields across all three databases. Each hit offers a front-page Preview, the full PDF and an HTML Text view. That is enough to pull up a patent someone sent you, or to run a first look at a two-word idea. It is not enough for a novelty search.

Advanced Search opens in its own browser tab with a free-text query box, the database selector, search options, a search history, a result list and a document viewer side by side. It offers two layouts: Quick Search, with the most-used panes, and Enhanced Search, which adds Tagged Documents, a Notes Viewer and a Hit Terms pane and highlights each keyword in its own color. Everything below is about Advanced Search. Searches do not carry over from Basic to Advanced, but the Basic tab stays open for comparison.

The three databases

All three are ticked by default. Untick one to leave it out.

The practical point is the gap before 1971. Older patents are in USOCR as machine-read scans, so spelling errors from the OCR and the limited field coding mean a keyword search there is patchy. For anything in a field where 1950s mechanical art is relevant, search by classification as well as keywords. And remember what is not here at all: the FAQ says Patent Public Search has no access to foreign patent databases.

Field codes

A term with no field code searches the whole document. To limit it, put the code after the term with a period on each side, or in square brackets: radar.ti. and radar[ti] are the same search. To apply a code to a whole expression, wrap the expression in parentheses first, as in (dog SAME cat).clm. The codes you will use most:

A few details that trip people up:

• CPC symbols go in without spaces or leading zeros: CPC G01S 17/931 becomes G01S17/931.cpc. The .cpc. field covers inventive and additional symbols; .cpci. is inventive only, and .cpcl. matches a whole subclass. The searchable-indexes table also documents range searching at subgroup level, with the example C07C51/43-64.cpc.
• Patent numbers need at least seven digits, padded with leading zeros, and no commas. Patents issued since June 19, 2018 can have eight digits. Design patents are D plus six digits, plant patents PP plus five, and published applications use the 11-digit YYYYnnnnnnn format, such as "20180093696".pn. Quote numbers so the system does not read them as L numbers.
• Several numbers at once: paste them separated by spaces and press the PN button next to Search. It applies .pn. to every item.
• Forward citations: 7029333.urpn. finds the patents that list US 7,029,333 among their cited references. It is the fastest way to see who built on a key patent.
• Names: inventor and attorney names are text fields, so use proximity rather than a fixed format: (smith NEAR2 john).in.

The full list, including assignee country, continuity data and combination sets, is in the USPTO's searchable indexes table. It also shows which codes work in which database. Several, such as .ab. and .spec., do not work in USOCR.

Boolean operators

If you type two words with no operator, Patent Public Search uses the Default Operator set in the search options. The USPTO's training material describes ADJ as the default; check the Options panel before you trust a query like cars automobiles vehicles, which means three ORs if the default is OR and a three-word phrase if it is ADJ. Use parentheses whenever you mix operators.

Proximity: ADJ, NEAR, WITH and SAME

Proximity is what makes full-text patent searching usable. A patent that says "sensor" 80 times and "lidar" once is rarely about a lidar sensor. These operators are taken from the USPTO's Advanced Search quick reference guide:

Stopwords are not counted. Words like "a", "the", "to" and "and" are not indexed in text fields, and Patent Public Search ignores them when it measures distance. So analog ADJ digital ADJ computer finds "analog to digital computer", and DNA ADJ3 computer finds "DNA, then storing it on the computer". If you need to search for the word AND or OR itself, put it in quotation marks in upper case.

As a rule of thumb, NEAR5 to NEAR10 suits two concepts that should appear in the same clause, WITH suits two features of the same component, and SAME suits a feature and the context it is used in. ADJ is best kept for fixed terms of art.

Truncation, wildcards and the options panel

• ? matches exactly one character anywhere in a word: m?cro finds micro and macro.
• $n matches up to n characters: micro$3 finds microvia, microbio, microsec and microgel.
• $ on its own is unlimited truncation: calibrat$.

Two limits from the FAQ stop a query from running at all. If any single term expands to more than 20,000 matching terms (the USPTO's example is A$), the query fails. And if the numbers in your truncations multiply to more than 125, it fails too: A$32B$4 is 128 and will not run. Give truncated stems at least four or five letters.

The Options panel under the query box has two switches that do some of this work for you. Plurals adds singular and plural forms (widget and widgets, company and companies). British Equivalents adds British spellings, so color also finds colour and tire finds tyre. Turn both on for keyword searches and you can drop a lot of truncation.

Dates

Dates are YYYYMMDD and years are four digits. You can search a single date as a field (20150217.pd.), or compare with an @ prefix on the field:

pd is publication (issue) date, ad the application filing date, py and ay their years. Foreign priority dates have their own field, .prad. (for example 20001111.prad.). When a prior-art cut-off is tight, still check the effective filing date on each close document by hand.

A worked search, step by step

Say the invention is a method for recalibrating a vehicle's lidar while driving. Every statement you run is saved as an L number in the Search History, and you can reuse it in later queries as L1 or just 1. A sensible sequence:

1. L1

   (lidar OR radar) ADJ4 sensor

   The USPTO's own example. Catches "lidar sensor" and "radar range sensor" but not a document that mentions lidar on page 2 and a sensor on page 40.

2. L2

   (calibrat$ NEAR5 (lidar OR radar)).clm.

   Calibration language in the claims, where it matters most for novelty. calibrat$ picks up calibrate, calibrated, calibrating and calibration.

3. L3

   G01S7/497.cpc. OR G01S17/931.cpc.

   Two CPC groups: means for monitoring or calibrating lidar-type systems, and lidar for anti-collision of land vehicles.

4. L4

   (L1 AND L2) OR (L3 AND calibrat$)

   Combines the earlier sets by their L numbers instead of retyping them.

5. L5

   L4 AND @ad<20230315

   Keeps documents filed before a hypothetical priority date of March 15, 2023. For prior art you care about the effective filing date, so check the dates of anything close by hand.

Then review. The result list shows 500 documents at a time and loads more as you scroll; results are grouped by family, with a "+" count for the other US family members. Click the Relevancy column heading twice to put the highest TF-IDF scores first. Open the closest hits, read the claims, and run their numbers through .urpn. to follow the citation trail forward. The CPC symbols on the best hits are often better than the ones you started with: look them up in the CPC scheme and run them as a new L set. Our CPC classification guide explains how to read and choose them.

Viewing documents and images

In Advanced Search, double-click a row in the results to open it in the Document Viewer. You can switch between text and image views and open up to three viewers side by side, for example the text of one document next to the drawings of another. The KWIC (keyword in context) button cuts the text down to paragraphs that contain your search terms, which is the quickest way to judge a long specification. In image view you can zoom from 5% to 200%, fit to width, rotate and invert, and page through drawings with the numeric keypad. Highlights do not show on images, only in text.

For a shareable PDF, Basic Search is the better tool. Its PDF view gives a permanent link, and the USPTO's PDF links guide documents the pattern: image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/ followed by the seven- or eight-digit patent number, D plus six digits for designs, PP plus five for plants, or the 11-digit publication number. The Advanced interface does not offer these direct links.

Saving and exporting your work

This is the weakest part of the tool, so plan for it.

• No saved workspaces. The FAQ says saving a workspace is currently unavailable. Notes you add to images are lost when the session ends.
• Print the history. The print icon in Search History, Search Results, Tagged Documents and the Notes Viewer is the official way to keep a record. Print to PDF and you have a dated search log, which you should keep anyway.
• Export to CSV. The Export documents icon downloads up to 10,000 results. If you have more than 500, scroll to the end first so they are all loaded. Expand the "+" families before exporting if you want the family members in the file.
• Tag as you go. Tag groups (keyboard shortcuts on the numeric keypad) let you sort hits into "closest", "background" and so on, and the "Create L# for All Tag" button turns your tagged documents into a search set.

Limitations to keep in mind

• US only. A US-only search misses European, Japanese, Chinese, Korean and PCT publications. Run the same concepts in Espacenet and Google Patents.
• No semantic search. The USPTO says so directly. If you do not guess the words the drafter used, the document does not come back.
• No non-patent literature. Papers, standards and product manuals are prior art too.
• Weak pre-1971 text. OCR text with limited fields; lean on classification there.
• Session-based. Thirty minutes idle and the workspace is gone.

The USPTO's own multi-step search strategy says much the same: brainstorm synonyms, search keywords, read the closest documents in full, expand with CPC, follow cited references, then broaden to foreign patents and non-patent literature. Our guide to building a patent search string covers the synonym and proximity side in more depth.

More USPTO guides

• How to file a provisional patent application (US)

  What a US provisional must contain, the USPTO fees, the 12-month deadline under 35 U.S.C. 119(e), and when to skip it.

• USPTO patent fees (2026)

  Every USPTO patent fee for large, small and micro entities, from filing to maintenance, with a fee calculator.

• Patent drawing requirements: USPTO, EPO and India

  37 CFR 1.84, the EPO rules that replaced Rule 46 EPC, and Indian rule 15, compared side by side.

• How to write patent claims: USPTO, EPO and India

  Claim structure and worked examples, then the claim rules and fees at the USPTO, the EPO and the Indian Patent Office, side by side.

• How to respond to a USPTO office action

  Reply deadlines and extension fees, 101, 102, 103 and 112 rejections, interviews, and options after a final rejection.

• Types of patent searches, and which one you need

  Patentability, freedom-to-operate, invalidity and landscape searches compared by purpose, timing, scope and deliverable.

• Patentability search: how to check novelty before you file

  What counts as prior art under 35 U.S.C. 102 and Art. 54 EPC, the grace period gap, search steps and how to read results.

• Freedom-to-operate search in the US and Europe

  In-force claims only, legal status checks at the USPTO, EPO and UPC, FTO opinions after Halo, and design-arounds.

• Invalidity search: prior art to challenge a patent

  IPR, PGR, EPO opposition and UPC revocation deadlines, prior art dates, standards documents and claim charts.

• Patent landscape analysis, step by step

  Building a CPC and keyword dataset, cleaning families and names, the metrics that matter and the 18-month publication lag.

• Google Patents search guide

  Search operators and fields, Boolean and proximity syntax, non-patent literature, and where Google Patents falls short of the official databases.

• The Cooperative Patent Classification (CPC), explained

  How CPC symbols are built, CPC against IPC, the Y section, how to find the right class and how to search it in each database.

• Patent search Boolean operators and search strings

  Boolean, proximity and truncation syntax compared across Patent Public Search, Espacenet, Google Patents and The Lens, with semantic search for contrast.

• How to respond to a 35 U.S.C. 101 rejection

  The Alice/Mayo steps in MPEP 2106, Ex parte Desjardins and the 2024-2026 USPTO guidance, Berkheimer evidence and Rule 132 eligibility declarations.

• How to respond to a 35 U.S.C. 102 rejection

  Anticipation under MPEP 2131, AIA 102(a)(1) and (a)(2), the 102(b) exceptions, inherency and Rule 130 declarations.

• How to respond to a 35 U.S.C. 103 rejection

  Graham and the KSR rationales in MPEP 2143, teaching away, motivation to combine, secondary considerations with nexus, and Rule 132 evidence.

• How to respond to a 35 U.S.C. 112 rejection

  Written description and enablement after Amgen, 112(b) indefiniteness, 112(f) means-plus-function after Williamson, and 112(d) dependent claims.

• The PCT application: timeline, fees and national phase

  The international phase month by month, receiving Office and ISA fees in CHF, USD and EUR, national phase deadlines by office, and a deadline calculator.

• Entering the US national stage under 35 U.S.C. 371

  The 30-month deadline and revival, the 371 requirements, national stage fees by entity size, and 371 versus a bypass continuation.

• The US foreign filing license (35 U.S.C. 184)

  When a US-made invention needs a license to be filed abroad, the six-month rule, expedited and retroactive licenses, and the Indian and European equivalents.

• Filing a US patent from Europe or India

  The 2026 US practitioner rule for foreign applicants, Paris priority and certified copies, small entity status, PCT or direct, fees and translations.

• What is a utility patent?

  What a US utility patent covers under 35 U.S.C. 101, the parts of the application in 37 CFR 1.77 order, the 20-year term and USPTO costs.

• Design patents in the United States

  What a design patent protects, drawings and the single claim, the 15-year term, Hague filings, LKQ v. GM, and design vs utility patents.

• How to file a nonprovisional patent application

  Required parts and fees, claiming a provisional within 12 months, DOCX filing in Patent Center, and what happens after you file.

• Provisional vs nonprovisional patent application

  The two US filings side by side, the cost of each route, the effect on term and publication, and a guide to which to file.

• Continuation, CIP and divisional applications

  Copendency, patent term, double patenting and terminal disclaimers, the 2025 continuing application fee, and continuation strategy.

• How much does a patent cost?

  USPTO fees by entity size from filing to the last maintenance fee, what drives professional fees, EPO fees, and an estimator.

• How to patent an idea in the US

  Nine steps from patentability and search to provisional filing, Patent Center, examination and maintenance, with the USPTO's free help programs.

• Small entity vs micro entity status

  Who qualifies under 37 CFR 1.27 and 1.29, the 2026 income limit, SB/15A and SB/15B, license traps, fixing errors, and an eligibility checker.

• How long does a patent last?

  US utility and design terms, patent term adjustment and extension, terminal disclaimers, maintenance fee deadlines, Europe and India, with an expiry estimator.

• Can AI write a patent application?

  What AI drafting does well and badly, the USPTO and EPO positions on AI tools, AI inventorship after 2025, and confidentiality.

• Restriction requirements and election of species

  How to answer a USPTO restriction or election of species requirement, from traverse and rejoinder to divisionals and unity in 371 cases.

• Options after a final rejection

  Amendment after final, advisory actions, the end of AFCP 2.0, RCE, pre-appeal and appeal, with fees, timing and USPTO outcome data.

• Request for continued examination (RCE)

  What 37 CFR 1.114 requires, first and later RCE fees, patent term effects, and when an RCE beats an appeal.

• Information disclosure statements (IDS)

  The duty of disclosure, IDS timing windows and fees, the 2025 size fee, EPO search reports, Therasense and QPIDS.

• PTAB ex parte appeals

  Notice of appeal to decision step by step, with fees, deadlines and the PTAB's FY 2026 pendency and outcome statistics.

• Track One prioritized examination

  Track One requirements, fees by entity size, the 20,000 annual cap and USPTO timing data, plus PPH and age or health petitions.

• 35 U.S.C., annotated: US patent law section by section

  The current text of 34 key sections of Title 35 with plain-English summaries, key cases, 37 CFR rules and MPEP references.

All guides, by patent office