Professional patent searches cost $500 to $3,000. A DIY search using free tools (Google Patents, USPTO Patent Public Search, PQAI) takes 2 to 4 hours and catches most prior art. Either way, searching before filing tells you whether someone has already patented your invention before you spend $5,000 to $15,000+ on the full application.
The USPTO examiner will search for prior art regardless. The difference is timing. If you search first, you know what you’re up against. You can adjust your claims, refine your invention, or decide not to file and save the money. If you skip the search, you find out what exists only after you’ve paid for a complete application.
Why Search Before Filing
Three reasons.
1. Save money. If your invention already exists in a granted patent, there is no point filing. A search costs either nothing (DIY) or $500 to $1,500 (professional). A wasted patent application costs $5,000 to $15,000+. The math is straightforward. See our full patent cost breakdown for filing price ranges.
2. Avoid rejection. The USPTO rejects applications that fail the novelty and non-obviousness requirements. If a prior patent covers your invention, the examiner will cite it and reject your claims. Finding that reference yourself first means you can either abandon the filing or design around the prior art before spending money on the application.
3. Strengthen your claims. Even if your invention is patentable, knowing the prior art helps your attorney write better claims. When you know what already exists, you can draft claims that clearly distinguish your invention from prior references. This reduces the number of office actions and speeds up prosecution.
Free Patent Search Tools
You do not need to pay for a patent search database. Four free tools cover almost everything a professional has access to.
| Tool | Best For | Coverage | Interface |
|---|---|---|---|
| Google Patents | Quick keyword searches, exploring related patents | US, EP, WO, JP, KR, CN, and others | Simple, Google-style search |
| USPTO Patent Public Search | Official US patent records, advanced field searches | All US patents and published applications | Advanced but has a learning curve |
| PQAI | AI-powered semantic search, finding conceptually similar patents | US patents | Paste a description, get results ranked by relevance |
| Espacenet | International patent coverage, classification browsing | 100+ countries via EPO | Good classification search tools |
Google Patents is the best starting point. It works like a regular Google search. Type in keywords describing your invention and browse the results. It also shows patent citations, letting you trace related patents forward and backward in time.
USPTO Patent Public Search (formerly EAST/WEST) is the same tool patent examiners use. It supports Boolean operators, field-specific searches (title, abstract, claims), and classification code searches. The interface is less intuitive than Google Patents, but it gives you more control over your queries.
PQAI takes a different approach. Instead of keywords, you paste a description of your invention and the AI finds conceptually similar patents. This is useful when you’re not sure which keywords to use, or when your invention could be described in multiple ways.
Espacenet is run by the European Patent Office and gives you the widest international coverage. If your invention might be patented in other countries, start here. Its classification search tools are also strong.
Step-by-Step DIY Search Process
A thorough DIY search takes 2 to 4 hours. Here is how to do it.
Step 1: Define Your Invention Clearly
Before you start searching, write down exactly what your invention is. Not the problem it solves. The specific structure, process, or composition that makes it work. Focus on the novel elements.
Bad: “A better way to keep food fresh.”
Good: “A container with a silicone lid that uses a manual pump mechanism to create a partial vacuum inside the container, reducing oxygen contact with the food.”
The more specific your description, the better your search queries will be.
Step 2: Generate a Keyword List
Break your invention into its core components and list synonyms for each one. Patent applicants from different industries and eras use different terminology for the same thing.
For the vacuum food container example:
| Component | Synonyms |
|---|---|
| Container | vessel, receptacle, housing, enclosure, box |
| Lid | cover, cap, seal, closure |
| Vacuum pump | air removal mechanism, suction device, evacuation means |
| Silicone | elastomeric, flexible polymer, resilient material |
| Food preservation | food storage, perishable storage, freshness maintenance |
Combine these synonyms into different search queries. Cast a wide net first, then narrow down.
Step 3: Search Google Patents
Go to patents.google.com and start with broad keyword combinations.
Try several queries:
- “vacuum food container silicone lid”
- “food storage vessel evacuation pump”
- “airtight container manual suction”
For each relevant result you find, read the abstract and look at the drawings. If it seems close to your invention, read the claims section. The claims define exactly what the patent protects. Two inventions can have similar descriptions but very different claims.
Step 4: Use Classification Codes
This is the step most DIY searchers skip, and it’s the one that matters most.
Every patent is assigned one or more Cooperative Patent Classification (CPC) codes. These codes group patents by technology, not by the words used to describe them. A vacuum food container might use different words than yours but share the same classification code.
When you find a relevant patent on Google Patents, look at its CPC codes (listed on the patent page). Common codes for our example might include:
- B65D 81/20 (containers with means for maintaining articles at reduced pressure)
- A47J 47/02 (food storage containers)
Click on the classification code in Google Patents to see all patents in that class. This surfaces patents your keyword search missed because they used different terminology.
You can also browse the full CPC classification tree at the USPTO CPC site to find relevant codes for your technology area.
Step 5: Chase Citations
Patent citations are a gold mine. Every patent lists the prior art it references (backward citations) and later patents cite the original reference (forward citations).
When you find a patent that is close to your invention:
- Check its references. Look at the patents it cites. These are the prior art the applicant and examiner considered most relevant.
- Check who cited it. On Google Patents, click “Cited by” to see later patents that reference this one. These are newer inventions in the same space.
- Repeat. Follow the citation chain in both directions. You’ll build a map of the technology area within two or three hops.
Citation chasing often surfaces the most relevant prior art because it follows technological lineage rather than relying on keywords.
Step 6: Search Non-Patent Literature
Prior art is not limited to patents. Published papers, product manuals, conference presentations, and even YouTube videos can count as prior art if they were publicly available before your filing date.
Use Google Scholar for academic papers. Search for your invention’s key concepts. If your invention is in a field with active academic research, this step is especially important.
But academic papers are just the start. Technical standards documents, product catalogs, industry white papers, conference proceedings, and trade publications all count as prior art. So do product listings on Amazon or user manuals posted online. The USPTO examiner will consider anything that was publicly available before your filing date, regardless of format. Cast a wide net.
Also search for commercial products. If a product already exists that does what your invention does, the product itself may be prior art, even if no patent was filed on it.
Step 7: Document Everything
Keep a record of every search query you ran, every relevant patent you found, and your assessment of how each one differs from your invention. This documentation serves two purposes:
- Your own analysis. When you review your results, you can identify which aspects of your invention are truly novel.
- Duty of disclosure. Patent applicants have a legal duty to disclose known prior art to the USPTO. If you find relevant references during your search, you must submit them with your application (on an Information Disclosure Statement, or IDS). Failing to disclose known prior art can invalidate your patent later.
When to Hire a Professional
A DIY search is a solid first pass. It will catch the obvious prior art and give you a general picture of the field. But it has limits.
Professional patent searchers have skills and tools that improve the hit rate:
- Classification expertise. They know which CPC and IPC codes to search without trial and error. This is the single biggest advantage. Classification-based searching catches references that no keyword search will find.
- Commercial databases. Tools like Derwent Innovation, PatSnap, and Orbit have better search interfaces, AI-powered similarity matching, and broader international coverage than the free tools.
- Experience reading claims. A professional searcher can quickly assess whether a reference actually anticipates your invention or just looks superficially similar.
Cost of a Professional Search
| Invention Complexity | Typical Cost | Turnaround |
|---|---|---|
| Simple mechanical invention | $500 to $1,500 | 1 to 2 weeks |
| Moderate complexity (electronics, consumer products) | $1,000 to $2,000 | 1 to 2 weeks |
| Complex technology (software, biotech, semiconductors) | $1,500 to $3,000+ | 2 to 3 weeks |
Many patent attorneys include a search as part of their initial engagement, bundled with a patentability opinion. Others refer you to a dedicated search firm. Either approach works.
You can find patent attorneys on MadePatents and ask about search services when you reach out.
When a Professional Search Is Worth It
Your invention has commercial value. If you plan to invest significant money in manufacturing, marketing, or licensing, the search is cheap insurance.
Your field is crowded. Some technology areas (smartphones, medical devices, software) have dense patent coverage. A professional search in a crowded field catches references that a keyword search will miss.
You found close prior art in your DIY search. If your initial search turned up similar inventions, a professional can analyze the specific claim differences and give you an informed opinion on patentability.
You are filing a non-provisional application. If you’re going straight to a full filing (skipping the provisional), the stakes are higher. The non-provisional costs more and starts the examination clock.
When a DIY Search Is Enough
You are filing a provisional first. A provisional application establishes your filing date and gives you 12 months before you need the non-provisional. Your DIY search tells you whether to proceed, and you can commission a professional search during the provisional year before the non-provisional filing.
Your invention is in a niche area. If very few patents exist in your technology space, a keyword search will cover most of the relevant prior art.
You are early-stage and budget-constrained. A DIY search plus a provisional filing is a reasonable path for inventors who need to validate the concept before spending more. See our cost calculator for budget estimates.
What a Professional Search Report Includes
A good search report is more than a list of patents. It typically includes:
A summary of the search strategy. Which databases were searched, which classification codes and keywords were used, and what date range was covered.
A list of the most relevant prior art references. Usually 5 to 15 patents and published applications, ranked by relevance to your invention.
A claim chart or comparison. For the closest references, the report maps each element of your invention against the elements disclosed in the prior art. This shows exactly where your invention differs.
A patentability opinion. The searcher or attorney assesses whether your invention appears to meet the novelty and non-obviousness requirements given the prior art found. This is usually framed as a recommendation: proceed with filing, modify the invention, or do not file.
Citation of any non-patent literature found during the search, including products, publications, or standards.
How Search Results Affect Your Patent Strategy
The search does not just tell you yes or no. It shapes how you approach the filing.
No close prior art found. Good news, but not a guarantee. File with confidence, but expect the examiner to find additional references during prosecution. No search is exhaustive.
Similar inventions exist but differ in key ways. This is the most common outcome. Work with your attorney to draft claims focused on the specific elements that distinguish your invention. The differences you identified in your search become the foundation of your claim strategy. Understanding what qualifies as patentable subject matter helps here.
Very close prior art exists. Consider whether you can modify your invention to create meaningful differences. Sometimes a design change that improves the product also creates the patentable distinction you need. If the prior art is too close and no modification helps, it may be better to save the filing fees.
The prior art suggests your invention is obvious. Non-obviousness is a higher bar than novelty. Even if no single reference matches your invention, a combination of two or three references might make it seem obvious. A patent attorney can assess whether a combination rejection is likely and how to argue against it. Our guide on the three requirements for patentability explains this standard in detail.
The USPTO Search Fee
When you file a patent application, the USPTO charges its own search fee on top of your filing fee. This is separate from any search you did yourself.
| Entity Size | Provisional Search Fee | Non-Provisional Search Fee |
|---|---|---|
| Micro entity | N/A (no search fee for provisionals) | $140 |
| Small entity | N/A | $280 |
| Large entity | N/A | $700 |
The USPTO search fee pays for the examiner’s prior art search during prosecution. It does not replace your own search. The examiner’s search happens months after filing, and by then you’ve already spent money on the application. Searching first is still the better approach.
Start Your Search Today
A patent search is the first real step in the patent process. Before you draft an application, before you hire an attorney, before you spend a dollar on filing fees, spend a few hours on Google Patents. You’ll learn more about your invention’s position in the market from two hours of searching than from weeks of guessing.
If the results look promising and you’re ready to move forward, use our patent cost calculator to estimate your total filing budget, or browse patent attorneys to find a professional who can take you from search to filing.
