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Company lists · Data refreshed September 2026

Top 25 Custom web software agencies based in Seattle, United States

Compiled by the RevenueBase Data Team Data refreshed Sep 24, 2026 83 companies tracked

RevenueBase identified 83 custom web software agencies headquartered in Seattle, United States as of September 2026 and tracks 418 professional contacts across them, including 100 with verified work emails. New York is the largest hub.

This list covers custom web software agencies headquartered in Seattle, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 24, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 24, 2026 86% judged on-target in blind review
83Companies
418Contacts tracked
100Verified emails
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The 25 largest custom web software agencies based in Seattle, United States

Ranked by team size
Top 25 of 83 custom web software agencies based in Seattle, United States, ranked by team size, largest first. Data refreshed Sep 24, 2026. RevenueBase Smart Search rates how each company's information relates to custom web software agencies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1
Fast Track Team
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202651-20028 contacts →

Partial evidence

“Fast Track creates cutting edge websites and web applications for businesses of all sizes faster and better than anyone else in the business.”

Source: RevenueBase Database · checked Sep 24, 2026
2
Exit83 Consulting
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202651-20025 contacts →

Partial evidence

“Since 2007, EXIT83 Consulting has been assisting companies with Website Development, Software Architecture, Mobile Application Development, Business Analysis and Fundraising…”

Source: RevenueBase Database · checked Sep 24, 2026
3
Pubgenius INC
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5025 contacts →

Partial evidence

“At pubGENIUS we build software that helps great ideas become real products.”

Source: RevenueBase Database · checked Sep 24, 2026
4
NEW Normal
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5025 contacts →

Strong evidence

“NewNormal builds custom software and lasting partnerships Since 2012 we’ve helped clients turn ideas into products that scale.”

Source: RevenueBase Database · checked Sep 24, 2026
5
NWOS
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-1020 contacts →

Partial evidence

“NWOS - Northwest Open Source provides Web application development and hosting across various industries.”

Source: RevenueBase Database · checked Sep 24, 2026
6
Culture Foundry
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-5016 contacts →

Partial evidence

“Websites and web applications.”

Source: RevenueBase Database · checked Sep 24, 2026
7
Lunarbyte
Strong evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-1012 contacts →

Strong evidence

“Lunarbyte is a custom software and product development firm trusted by teams across industries to deliver dependable, scalable software solutions that drive real business results.”

Source: RevenueBase Database · checked Sep 24, 2026
8
Bizango
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-108 contacts →

Partial evidence

“We're a full-service web design and online marketing agency dedicated to serving businesses, bestselling authors, startups and e-commerce.”

Source: RevenueBase Database · checked Sep 24, 2026
9
Fostec
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-108 contacts →

Indirect evidence

“Founded in 1998, Fostec is a client-focused Information Technology consulting firm that designs solutions and provides technical expertise to small and mid-sized businesses…”

Source: RevenueBase Database · checked Sep 24, 2026
10
Gols INC
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-507 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 24, 2026
11
Montana Banana WEB Design & Development
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-106 contacts →

Partial evidence

“Montana Banana is a Seattle-based web development company specializing in e-commerce integrations, user-friendly shopping experiences, web accessibility, and mobile apps.”

Source: RevenueBase Database · checked Sep 24, 2026
12
Pythonwise INC
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-506 contacts →

Indirect evidence

“Pythonwise Inc is leading provider of Information Technology consulting and business process services.”

Source: RevenueBase Database · checked Sep 24, 2026
13
Alpha Encoded
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-106 contacts →

Indirect evidence

“Based in the tech-centric city of Seattle, Alpha Encoded stands at the forefront of digital innovation.”

Source: RevenueBase Database · checked Sep 24, 2026
14
Hard Refresh
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-105 contacts →

Indirect evidence

“Better for business.”

Source: RevenueBase Database · checked Sep 24, 2026
15
Pacific Automation Group
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-104 contacts →

Partial evidence

“We create and deploy tailor-made software solutions aimed at enhancing efficiency and optimizing operations for a diverse range of clients, spanning individuals, businesses…”

Source: RevenueBase Database · checked Sep 24, 2026
16
Cogenix
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-104 contacts →

Partial evidence

“Cogenix offers business consulting, application development and software integration services to our client base.”

Source: RevenueBase Database · checked Sep 24, 2026
17
Zaifworks LLC
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-104 contacts →

Partial evidence

“Zaifworks is software development and cloud consulting firm that specializes in healthcare, real-estate and it services industries.* We transform, deploy and support what you are…”

Source: RevenueBase Database · checked Sep 24, 2026
18
Mahogany And Mango LLC
Strong evidenceSeattle, United StatesHQ checked Sep 24, 20261-103 contacts →

Strong evidence

“Helping small businesses and non-profit organizations build their online presence with custom-built websites & web applications.”

Source: RevenueBase Database · checked Sep 24, 2026
19
Ignia, LLC
Strong evidenceSeattle, United StatesHQ checked Sep 24, 20261-103 contacts →

Strong evidence

“Ignia is a software development agency specializing in the architecture, implementation and maintenance of localized, data-driven, multi-device web applications.”

Source: RevenueBase Database · checked Sep 24, 2026
20
NEW Theory
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 202611-503 contacts →

Partial evidence

“New Theory is a creative web agency that pushes design and technology for a shared, frictionless future.”

Source: RevenueBase Database · checked Sep 24, 2026
21
Webkey
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-103 contacts →

Partial evidence

“Taking care of the needs of companies small and large on the web has been our business for over two decades.”

Source: RevenueBase Database · checked Sep 24, 2026
22
White Brick
Indirect evidenceSeattle, United StatesHQ checked Sep 24, 20261-103 contacts →

Indirect evidence

“Since 2008 I have been producing websites, marketing, and tech infrastructure for small businesses in the Seattle area.”

Source: RevenueBase Database · checked Sep 24, 2026
23
Swiss IT Solutions
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-103 contacts →

Partial evidence

“Swiss It Solutions is a technology company offering web design and IT consulting services.”

Source: RevenueBase Database · checked Sep 24, 2026
24
Seattle WEB Group
Indirect evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-102 contacts →

Indirect evidence

“Intelligent website development takes the type of expertise that only comes with years of real experience.”

Source: RevenueBase Database · checked Sep 24, 2026
25
Panolabs
Partial evidenceSeattle, WA, United StatesHQ checked Sep 24, 20261-102 contacts →

Partial evidence

“We are a full-stack Web development and technical consulting company based in Seattle, Washington.”

Source: RevenueBase Database · checked Sep 24, 2026

Showing 25 of 83 custom web software agencies based in Seattle, United States

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Custom web software agencies based in Seattle, United States at a glance

As of Sep 24, 2026
23.9%Verified-email coverage
5.0Average contacts per company
1-10Median size (employees)
598.8%Largest-city concentration · New York
Sep 24, 2026Page data refreshed

Companies by employee count

1-10
58
11-50
22
51-200
2
501-1,000
1

Email recency for this list is measured across the whole United States list rather than for Seattle, so it is reported there. Company counts and contact totals on this page are exact for Seattle, over 83 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among custom web software agencies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Seattle, United States whose own description of what they do matches “custom web software agencies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names custom web software agencies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among custom web software agencies, and records with no verified work email. Companies headquartered outside Seattle are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 100 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 24, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Custom web software agencies by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names custom web software agencies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many custom web software agencies are there based in Seattle, United States?

RevenueBase identified 83 custom web software agencies headquartered in Seattle, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Fast Track Team, headquartered in Seattle, tops this list with the largest team on record.

Which city has the most custom web software agencies?

New York leads with 497 headquartered companies, followed by Austin (252) and Los Angeles (194).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 100 verified decision-maker contacts tracked across these 83 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 24, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.

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