Silicon Valley investors are piling into companies that want to drag the $160-billion-a-year business of arranging cargo shipments into the Internet age.

Companies that coordinate shipping for retailers and manufacturers, known as freight forwarders, do everything from finding the right combination of trains, planes and trucks for a speedy delivery to pushing shipments through customs.

Forwarders’ work touches much of global trade, but many customers complain that the industry relies on outdated technology: Orders are often placed via phone call, or even fax, and tracked using emailed spreadsheets.

Dozens of companies are pitching themselves as freight forwarding’s Expedia Inc. EXPE -2.68% or Priceline Group Inc., betting that slick online platforms and automated price quotes will convince shippers to break ties with established forwarders. Many freight veterans and analysts are skeptical of these efforts, saying forwarding is too complex and too dependent on longstanding relationships for new online entrants to compete.

But some of Silicon Valley’s biggest venture-capital firms are betting on the new technology. Since the start of 2014, venture-capital firms have pumped over $1 billion into startup freight-forwarding companies, twice the amount invested in the five years before that, according to research firm Pitchbook Data. It is a large sum for an industry that wasn’t on most tech investors’ radar even two years ago, Pitchbook analysts say.

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Among the most recent deals: Founders Fund, backed by Paypal Holdings Inc. creator Peter Thiel, last month led a $20 million round of funding for a freight-forwarding startup called Flexport Inc., which offers online booking and tracking for cargo shipments.

“You have direct information without having to go through this game of telephone that you had to historically play with freight brokers,” said Trae Stephens, a principal with Founders Fund.

So far, startups haven’t seen the same growth as consumer travel websites did a decade ago.

Some shippers have unique demands depending on their supply chains and distribution networks that aren’t easily handled by an automated pricing platform. Freight forwarders provide add-on services, such as using relationships with shipping lines and trucking companies to guarantee clients’ goods are first in line when there are delays. Some of the new pricing platforms aren’t equipped to assist with customs, a crucial service for international shippers.

“Many startups just want to bring together a carrier and a shipper—they underestimate the value-add of a forwarder,” said Matthias Hanke, a Zurich-based transportation consultant.

Others see the recent crop of startups filling certain shippers’ needs, particularly for small companies. In a survey of shippers by Penn State Professor C. John Langley Jr. with the consulting group Capgemini, 75% said the logistics industry could benefit from better technology, and only 40% said logistics companies were using technology in the quote process.

Flexport says it provides rate quotes more quickly than traditional freight-forwarders by automating much of the process. The company also completes customs paperwork electronically and provides real-time air and ocean shipment tracking.

Brian Hahn, co-founder of Nomad Goods, says it takes him just a few minutes to initiate a shipment of his company’s phone chargers from China to the U.S. using Flexport. Mr. Hahn said Nomad is growing fast and the prospect of shipping his gadgets using traditional freight forwarders is “complicated and scary.”

“I’m not trying to be a logistics expert here,” he said. “We’re trying to be a product company that delivers stuff on time.”

Startups also see an opportunity to break into a market where even some of the largest established forwarders have struggled to integrate new technology.

Tel Aviv-based Freightos markets its technology to conventional freight-forwarders, who use it to gather disparate sources of data on carrier rates, port handling fees, fuel surcharges and other expenses in order to generate price quotes. The company has received $9 million in venture funding.

“The right technology is badly needed,” said Niels Erich, spokesman for a group of 15 major shipping lines known as the Transpacific Stabilization Agreement.

Analysts say if today’s major players in global freight forwarding can’t work with the new technology, they’re likely to lose market share.

“Ultimately the technology will advance, as it always does,” said Alex Le Roy, an analyst with research firm Transport Intelligence. “And those who do not adapt will fall behind.”

Write to Erica E. Phillips at erica.phillips@wsj.com