Startup Deep Dive : Doubtnut — offered $150M by Byju’s, sold to Allen for $10M

In December 2023, Allen Career Institute paid about $10 million (₹96 crore at $1 ≈ ₹96.0 as of 18 September 2026, Trading Economics) for an edtech company that Byju’s had once offered somewhere between $125 million and $150 million to buy outright. Doubtnut, the app that let a student in a small town photograph a maths problem and get a video solution back in seconds, had raised more than $50 million from Tencent, Sequoia and James Murdoch’s Lupa Systems along the way.

What happened between the offer and the sale is a fairly ordinary story about an extraordinary user base: tens of millions of students who loved a free product, and a business model that never quite worked out how to charge them. Doubtnut’s decline was not a scandal or a single bad decision. It was a slow-burning mismatch between reach and revenue, and it is worth tracing in detail because so many “free-first” Indian apps are still betting they can fix that mismatch before the money runs out.

Quick facts

What they do

Doubtnut sells a doubt-solving service to school and competitive-exam students, most of them preparing for board exams, IIT-JEE or NEET. The core idea has stayed constant since 2017: a student photographs a question they are stuck on, and the app returns a step-by-step video solution, drawing on a large pre-recorded library and, where nothing matches, newly filmed answers. Around that core, Doubtnut layered live online classes, YouTube channels in Hindi and English, and NCERT-aligned study material, aimed squarely at students in small towns who could not afford, or could not access, a coaching institute. As of this writing the company operates as a subsidiary of Allen Career Institute, the Kota-based test-prep group, which acquired it in December 2023.

The origin

Tanushree Nagori and Aditya Shankar met at IIT Delhi and worked in planning and consulting roles in India and the United States before turning to education. In 2009 they started a coaching venture called Class 21A, tutoring students in grades 9 through 12 in maths and science around Gurugram. It worked, in the way most good coaching centres work: one classroom, one batch, one teacher at a time. It also could not scale, and Nagori has said that even families spending over Rs 1 lakh a year on coaching still could not get every doubt answered in time.

The fix they landed on was blunt rather than clever. In mid-2015, while still running Class 21A, the couple built a single-page app that let a student send a photo of a problem and receive a video answer over WhatsApp, sometimes days later. It was slow and manual, but it proved that a photograph of a handwritten question was a viable input, and that a video, not a text answer, was the format students actually wanted. The company was incorporated in 2016 as Class 21A Technologies, and the polished app, rebuilt around an automated question-matching engine, launched in October 2017 under the Doubtnut name. Maths came first, because the founders judged it the subject where students in grades 6 to 9 and in entrance-exam prep got stuck most often — and where a worked video, rather than a one-line answer, actually helped.

The struggle years

Doubtnut’s early growth curve looked enviable. By the end of 2019 it had around 1.1 million daily active users and 2.7 million Google Play downloads, and by January 2020 it was reporting over 13 million monthly active users across app, web, YouTube and WhatsApp, with 85 percent of them outside India’s ten largest cities. Underneath that reach, the company’s own filings tell a harder story.

• FY20: revenue of just Rs 8 lakh against a loss of Rs 26.26 crore, on total costs of Rs 27.3 crore — a company almost entirely unmonetised at scale (Entrackr, April 2022, citing RoC filings).
• FY21: revenue grew to Rs 2 crore, all of it from subscriptions, but the loss widened 3.89 times to Rs 102.32 crore as total cost rose to Rs 105.2 crore — the filing noted the company spent Rs 52.35 to earn every rupee of operating revenue (Entrackr, April 2022).
• Late 2020 into 2021: Doubtnut pushed into live, paid classes for classes 9 to 12 across state boards (CBSE, UP Board, Bihar Board, MP Board and others) in both Hindi and English medium, trying to convert its free doubt-solving audience into paying students — a pivot away from a purely free, ad-and-scale model.
• FY22: revenue rose to Rs 15.22 crore (Rs 10.83 crore from operations) but the loss jumped again to Rs 179.24 crore, on total expenditure of Rs 194.47 crore, of which Rs 72.39 crore was employee costs (Entrackr, March 2023).
• Early 2023: with “no new investors ready to rescue” the company, existing backers Sequoia, Omidyar and WaterBridge put in $2.5 million (about Rs 20 crore) through convertible notes rather than a priced round — a sign the company could not raise fresh outside capital (Entrackr, April 2023).
• By April 2023: Doubtnut had cut 30-40 percent of its workforce over the prior two quarters and shut its banking, SSC and other government-exam-prep verticals entirely, targeting break-even within 10-12 months (Entrackr and Digital Learning, April 2023).

None of this was hidden. The company’s own numbers, filed with the Registrar of Companies each year, show a business that kept growing its audience while its losses grew faster than its revenue — the definition of a model that has not been found yet.

The turning point

The clearest fork in Doubtnut’s road came in June 2020, when Byju’s — then still raising money at giant valuations and shopping for acquisitions across the smaller-city market Doubtnut had won — entered advanced talks to buy the company for a reported $125-150 million. Byju’s wanted exactly what Doubtnut had built: reach in tier 2 and tier 3 India that its own brand had not cracked. Unacademy had held preliminary talks too, and then dropped out.

The Byju’s deal never closed. Reporting from the time and since points to disagreements over valuation, and Doubtnut continued exploring options with other investors, including Prosus Ventures, without a deal materialising. On one side of that failed negotiation sat a $125-150 million offer at the peak of India’s edtech funding boom. On the other side, three and a half years later, sat a $10 million acquisition price from Allen Career Institute — a decline of roughly 93 percent in headline value, agreed after edtech funding had dried up, after two rounds of layoffs, and after existing investors had to prop up the company with a bridge note rather than fresh capital. The company that walked away from a nine-figure offer in 2020 sold for eight figures in 2023.

The money behind it

• Total raised: more than $50 million (about $52 million by most tallies) across roughly eight rounds between 2018 and the 2023 bridge note (TechCrunch, December 2023; Tracxn).
• Series A — January 2020: $15 million led by Tencent, with Sequoia India doubling its seed bet and participation from Omidyar Network, Japan’s AET Fund and Curefit founder Ankit Nagori; the round valued the company at close to $50 million (Entrackr and Inc42, January 2020).
• Series B — February 2021: about $31 million (Rs 183.3 crore) co-led by Susquehanna International Group (SIG) and James Murdoch’s Lupa Systems, with Sequoia Capital, Omidyar Network India and WaterBridge Ventures also investing; the round valued Doubtnut at Rs 880 crore (about $121 million) post-money, and left Tencent and Sequoia each holding a 12.9 percent stake (Entrackr, February 2021).
• Internal round — April 2023: $2.5 million (about Rs 20 crore) from existing investors Sequoia, Omidyar and WaterBridge, structured as convertible notes rather than a new priced round, after the company found no new external backer willing to lead (Entrackr, April 2023).
• Exit — December 2023: acquired by Allen Career Institute for about $10 million, a deal Allen and Doubtnut both declined to detail publicly beyond confirming it had closed (TechCrunch and Business Standard, December 2023).

What each investor changed: Sequoia backed Doubtnut from its seed stage through the final 2023 bridge note, the one investor present at both ends of the company’s life. Tencent’s Series A cheque, the largest single check at that stage, gave the company its first big war chest and a valuation marker near $50 million. SIG and Lupa Systems doubling the round size in 2021 pushed the valuation past $100 million at a time when Indian edtech funding was near its peak — money that funded the live-classes pivot and the hiring that followed, and that the company’s own FY21-FY22 filings show it burned through faster than it could replace.

How it makes money

Doubtnut’s core doubt-solving tool was always free — the company’s growth strategy depended on a low-friction, no-signup entry point that could spread in towns where a paid app was a hard sell. Money came from what sat around that free core.

• Subscriptions for live classes and structured courses (board exams, JEE, NEET) — in FY21, filings show subscriptions were effectively the company’s only revenue line, at Rs 2 crore (Entrackr, April 2022).
• Advertising on the free app and on YouTube — the company’s Hindi-medium YouTube channels were generating an estimated Rs 40 lakh a month in ad revenue by March 2023, and its class 9-10 Hindi-medium channel alone brought in Rs 79 lakh in March 2023, up from Rs 22 lakh a year earlier, a fourfold rise as views rose 70 percent (Entrackr, April 2023).
• Content and infrastructure partnerships with other education and publishing businesses, using Doubtnut’s video-answer library and AI question-matching as licensed infrastructure rather than a direct-to-student product.

The part most outside observers got wrong was assuming a free tool used by tens of millions of students should translate easily into revenue at a similar scale. It did not. Doubtnut’s own numbers show it spent Rs 52.35 to earn one rupee of operating revenue in FY21 and Rs 17.96 to earn one rupee in FY22 — an improving ratio, but one that started from a position so weak that even a big year-on-year gain left the company burning far more cash than it brought in. The margin, such as it was, sat in advertising on high-traffic Hindi-medium content and in the small slice of free users who converted to paid live classes — not in the core product that drove downloads.

The numbers

Figures below are as filed with the Registrar of Companies and reported by Entrackr; amounts are in Rs crore unless noted. FY23 loss was not available in public reporting at the time of writing and is left blank rather than estimated.

• FY20 to FY21: revenue rose from Rs 8 lakh to Rs 2 crore, but the loss widened 3.89 times (Entrackr, April 2022).
• FY21 to FY22: revenue roughly 5.3 times higher on the operations line, but the loss still grew, from Rs 102.32 crore to Rs 179.24 crore (Entrackr, March 2023).
• FY22 to FY23: revenue grew about 44 percent to Rs 26.6 crore, the first year the company reported alongside a sharp cost cut — monthly burn fell from Rs 10.6 crore in March 2022 to Rs 2.2 crore in March 2023, roughly an 80 percent reduction (Entrackr, April 2023).

Where the money comes from

• Geography: an estimated 85 percent of monthly active users came from outside India’s ten largest cities as of January 2020, the tier 2/tier 3/tier 4 base the company was built around (TechCrunch, June 2020).
• Language: Hindi-medium content was the company’s fastest-growing and best-monetising segment by FY23 — its Hindi-medium classes 9-10 YouTube channel’s ad revenue rose fourfold year-on-year to Rs 79 lakh in March 2023, and NEET Hindi-medium video views rose 13 times, from around 700,000 to 10 million views a month, between March 2022 and March 2023 (Entrackr, April 2023).
• Product line: by 2023 the company had narrowed from a broad exam-prep portfolio — school boards, JEE, NEET, banking and SSC government-exam prep — down to school boards, JEE and NEET only, after shutting the banking and SSC verticals (Entrackr and Digital Learning, April 2023).
• The surprise: the free, high-volume doubt-solving tool that built Doubtnut’s user base was not where the money sat. Revenue concentrated in paid live classes and in advertising on Hindi-medium YouTube content — a far narrower slice of the audience than the tens of millions who used the core app.

The risks

• Monetisation-to-scale gap: the company’s own RoC filings show it never closed the gap between user reach and paying users — FY22 revenue of Rs 15.22 crore against expenditure of Rs 194.47 crore is roughly a 13-fold mismatch, and it is the single risk that ultimately forced the sale (Entrackr, March 2023).
• Funding dependence in a cooling market: when Doubtnut needed fresh capital in 2023, existing investors would only extend a $2.5 million convertible note rather than a priced round, after the company failed to find a new lead investor — a direct consequence of the broader pullback in Indian edtech funding after 2021-22 (Entrackr, April 2023).
• Concentration under a single acquirer: since December 2023 Doubtnut’s fortunes are tied to Allen Career Institute’s strategy; Allen and Doubtnut both declined to disclose the financial terms of the deal, and Allen has not published separate financials for the Doubtnut business since the acquisition (Business Standard and TechCrunch, December 2023).

The takeaway

Doubtnut’s arc is a reminder that reach and revenue are not the same asset, and that raising money against reach can buy a company several years before that distinction gets enforced. Tens of millions of monthly users, 85 percent of them outside India’s biggest cities, was a genuinely rare position to be in in 2019 and 2020 — rare enough that Byju’s offered nine figures for it. But the filings for every year from FY20 to FY23 show a company that kept adding users faster than it worked out how to charge a meaningful share of them, and investors eventually stopped underwriting that gap. The lesson is not “monetise early” as a slogan; it is that a founding team should be able to name, in one sentence, which specific slice of its free users is expected to pay, and for what, well before the funding that lets it postpone that question runs out.

Frequently asked questions

Who founded Doubtnut and when?

Doubtnut was founded by the husband-wife duo Tanushree Nagori and Aditya Shankar, both IIT Delhi alumni. The company was incorporated in 2016 as Class 21A Technologies, building on a tutoring venture the couple had run since 2009, and the Doubtnut app launched in October 2017.

Who owns Doubtnut now?

Allen Career Institute, the Kota-based test-prep group, acquired Doubtnut in December 2023 for a reported $10 million. The founders have continued in operational roles as co-founders, with the company running as an Allen subsidiary (Business Standard and TechCrunch, December 2023).

How much funding did Doubtnut raise before being acquired?

Doubtnut raised more than $50 million across roughly eight rounds, including a $15 million Series A led by Tencent in January 2020 and a $31 million Series B co-led by SIG and Lupa Systems in February 2021, before a final $2.5 million convertible-note round from existing investors in April 2023 (Entrackr; TechCrunch, December 2023).

Why did Doubtnut sell for so much less than earlier offers?

In 2020, Byju’s held advanced talks to buy Doubtnut for a reported $125-150 million, but the deal collapsed over valuation disagreements. By December 2023, after years of losses far exceeding revenue and a cooling edtech funding market, Doubtnut sold to Allen Career Institute for about $10 million (TechCrunch, December 2023).

What was Doubtnut’s revenue and loss in its last reported years?

Per RoC filings reported by Entrackr, Doubtnut’s revenue was Rs 15.22 crore in FY22 (loss of Rs 179.24 crore) and Rs 26.6 crore in FY23, a roughly 44 percent rise; FY23 loss figures were not available in public reporting at the time of writing.

Sources

Figures are as of September 2026. Currency converted at $1 ≈ ₹96.0 as of 18 September 2026 (Trading Economics).

• TechCrunch, “Doubtnut, once offered a $150M deal from Byju’s, sells for $10M”, December 2023
• TechCrunch, “Indian edtech giant Byju’s in talks to acquire Doubtnut for more than $125M”, June 2020
• TechCrunch, “Two-year-old Indian edtech startup Doubtnut raises $15M”, February 2020
• TechCrunch, “Murdoch, Shankar’s Bodhi Tree invests $600M in Allen Career Institute”, May 2022
• Entrackr, “Six-year-old Doubtnut spent Rs 105 Cr to earn Rs 2 Cr in FY21”, April 2022
• Entrackr, “Doubtnut spent Rs 194 Cr to make Rs 10 Cr revenue in FY22”, March 2023
• Entrackr, “Exclusive: Doubtnut slashes costs by 80%, raises $2.5 Mn in internal round”, April 2023
• Entrackr, “Exclusive: Doubtnut raises $25 Mn in its Series B round”, February 2021
• Digital Learning (Elets), “Edtech firm Doubtnut lays off 40% workforce”, April 2023
• Forbes India, “Doubtnut: Doing more than maths”, 2018
• YourStory, “This Sequoia-backed edtech startup by IIT Delhi alumni…”, July 2019
• Business Standard, “Allen Career Institute acquires AI-enabled edtech platform Doubtnut”, December 2023
• Indian Startup News, “Allen Career Institute acquires Doubtnut for approx Rs 83 crore”, December 2023

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