When was ClearSign founded?

ClearSign was founded in 2008 and raised its 1st funding round 3 years after it was founded.

Where is ClearSign located?

ClearSign is headquartered in Seattle, United States.

How many employees does ClearSign have?

As of Sep 30, 2026, the latest employee count at ClearSign is 23.

Is ClearSign a funded company?

ClearSign is a funded company, having raised a total of $1.16M across 12 funding rounds to date. The company's 1st funding round was a $***** Seed round, raised on Feb 02, 2011.

When was the latest funding round of ClearSign?

ClearSign's latest funding was a $***** Post IPO round on Jul 22, 2026, with participation from 0 investor.

What is the annual revenue of ClearSign?

Annual revenue of ClearSign is less than $1M as on Dec 31, 2018

Where does ClearSign rank among its competitors?

ClearSign ranks 4th amongst 147 active competitors, of which 18 are funded. It stands 5th in terms of total funding among its competitors. The most recent competitor to raise funding was Asuene, which secured $41.7M in Jul, 2026.

Who are the top competitors of ClearSign?

ClearSign's top competitors include Tachyus, Asuene and Exposome. Among them, Asuene secured the most recent funding round in July, 2026.

ClearSign - 2026 Company Profile, Funding, Competitors & Financials

ClearSign is a public company based in Seattle (United States), founded in 2008. It operates as a Provider of combustion efficiency enhancement technology solutions. ClearSign has raised $1.16M in funding. The company has 147 active competitors, including 18 funded and 6 that have exited. Its top competitors include companies like Tachyus, Asuene and Exposome.

Company Details

Provider of combustion efficiency enhancement technology solutions. The company offers Duplex and Electrodynamic Combustion Control platform technologies that enhance the performance of combustion systems in a broad range of markets, including the chemical, petrochemical, refinery, power, and commercial boiler industries. Additionally, it offers retrofit strategies for superior emissions control and improved performance during combustion.

Website: clearsign.com
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Email ID: *****@clearsign.com

Key Metrics

Founded Year

2008

Location

Seattle, United States

Stage

Public

Total Funding

$1.16M in 12 rounds

Latest Funding Round

Post IPO, Jul 22, 2026, $*****

Investors

DOE & 1 more

Ranked

4^th among 147 active competitors

Annual Revenue

$0 - $1M as on Dec 31, 2018

Employee Count

23 as on Sep 30, 2026

Similar Companies

Tachyus & 151 more

Exit Details

Public

View ClearSign's full profile

ClearSign is associated with 3 legal entities given below:

Legal Entity Name	Date of Incorporation	Revenue	Latest Employee Count	Reports
Clearsign Combustion Corp CIN: 1434524 , United States, Active		$0 - $1M (As on Dec 31, 2018)	-	-
CLEARSIGN TECHNOLOGIES CORP CIN: 1434524 , United States, Active	Jun 13, 2023	$1M - $10M (As on Dec 31, 2025)	-	-
Clearsign Technologies Corporation CIN: 26-2056298 , United States, Active	Dec 31, 2007	-	16 (As on Dec 31, 2022)	-

ClearSign got listed on Apr 25, 2012.

Click here to take a look at ClearSign's IPO in detail

ClearSign has raised a total funding of $1.16M over 12 rounds. Its first funding round was on Feb 02, 2011. ClearSign has 2 institutional investors.

Here is the list of recent funding rounds of ClearSign:

Filter this list

Date of Funding	Funding Amount	Round Name	Post-Money Valuation	Revenue Multiple	Lead Investors	Other Investors
Jul 22, 2026	3274560	Post IPO	1518147	4437428	5264606	7493732
Dec 05, 2025	4011307	Grant (prize money)	2574667	3332553	1386131	OSTI
Jun 06, 2025	1982682	Grant (prize money)	2508566	4575542	1392426	OSTI

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View details of ClearSign's funding rounds and investors

ClearSign's employee count trend

ClearSign has 23 employees as of Sep 26. Here is ClearSign's employee count trend over the years:

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Top competitors of ClearSign include Tachyus, Asuene and Exposome. Here is the list of Top 10 competitors of ClearSign, ranked by Tracxn score:

Rank	Company Details	Short Description	Total Funding	Investors	Tracxn Score
1st	Tachyus 2013, Palo Alto (United States), Acquired	Developer of software for operational optimization and emissions management solutions	$46.9M	Founders Fund, Caffeinated Capital & 16 others	63/100
2nd	Asuene 2019, Tokyo (Japan), Series D	Provider of cloud software for carbon emission tracking and reporting	$111M	Sony Innovation Fund, Incubate Fund & 32 others	56/100
3rd	Exposome 2020, Mumbai (India), Seed	Provider of materials chemistry solutions for industrial air and water treatment	$4.04M	Colossa Ventures, Bhukhanvala Group & 11 others	55/100
4th	ClearSign 2008, Seattle (United States), Public	Provider of combustion efficiency enhancement technology solutions	$1.16M	DOE, OSTI	52/100
5th	Coolbrook 2011, Helsinki (Finland), Funding Raised	Developer of technology for electrification and decarbonization of heavy industry	-	ABB, Butterfly Ventures & 4 others	48/100
6th	Othersphere 2022, Victoria (Canada), Seed	Provider of a platform for infrastructure project development and site selection	$2.27M	Active Impact Investments, Keiki Capital & 2 others	47/100
7th	Yamna 2022, London (United Kingdom), Seed	Providing solutions to reduce greenhouse gas emissions	-	HYCAP	45/100
8th	360 ENERGY 1995, Ancaster (Canada), Unfunded	Provider of software solutions to reduce energy usage and carbon emissions	-	-	42/100
9th	Advanced Emissions Solutions 1997, Highlands Ranch (United States), Public	Provider of emissions control and water purification technologies	-	-	41/100
10th	Welspun Michigan 1988, Mumbai (India), Unfunded	Provider of sustainable solutions to control emissions from industrial plants	-	-	40/100