# Lingo.dev

Aiolum story: https://aiolum.com/story/lingo-dev/ · added 2026-11-12 · updated 2026-11-12

**In short.** Lingo.dev (Translation engine and quality scoring for software teams, with an open-source command line tool, United States): 5.4K GitHub stars on the open-source tool, November 2026. Evidence grade E: no revenue figure was checked. Team: 2 co-founders at the start in December 2023; 7 people on the Y Combinator page, read in November 2026. Launched 20 March 2024; still running.

Translation engine and quality scoring for software teams, with an open-source command line tool · United States · AI-native · team of 2 to 10 · still running · group: Developer tools and coding agents

- Outcome: 5.4K GitHub stars on the open-source tool, November 2026 (evidence grade of the headline number: E; no revenue figure)
- Launch: 20 March 2024; months from launch to the outcome: 31
- Team: 2 co-founders at the start in December 2023; 7 people on the Y Combinator page, read in November 2026
- Outside funding: US$4.2M, as the company states; no date or split given
- Main factor: Own problem
- Meters, 1 to 4: evidence strength 1, copyable pattern 2, capital needed 2
- Tags: AI-native, Small team, Funded, Running, B2B, Developer tools

Links:

- Visit lingo.dev: https://lingo.dev/

**The product.** A service that translates the text of a software product with large language models and scores each translation before it goes live. Teams configure a localization engine with a glossary, brand voice and model choice. They reach it through a free open-source command line tool, an API or a GitHub integration.

**Why it worked.** Lingo.dev started from a problem its two founders say they met in their own work. The people accountable for translations cannot read most of the languages. The company says its first product translated software with AI on every commit. It rebuilt the product around quality scoring for localization teams, and the pricing page lists a US$99 monthly plan.

Evidence grades: A = disclosed by a public company, a filing or a payment processor, or verified by one; B = two or more independent reports agree, or a journalist confirmed it; C = a founder claim that no one else verified; D = reported, not verified: one founder claim or a third-party estimate with no second source; E = no revenue figure found, so the headline is a non-money fact and the other facts carry their own grades; calc = computed on this page from graded facts.

## Summary

Lingo.dev sells localization for software: adapting a product's text to other languages. A localization engine is, in the company's words, a stateful translation API that holds a team's glossary, brand voice and model preferences. Retrieval augmented localization sends that stored context to the language model with every request. The company's open-source command line tool, under the Apache-2.0 license, pushes source files to an engine and writes the translations back.

Y Combinator names Max Prilutskiy and Veronica Prilutskaya as the founders. The company says it began in December 2023 at a hackathon at Cornell Tech, and that the work was full-time from February 2024. Its legal name in the footers is Replexica, Inc, and the first GitHub releases, from March 2024, carry the name Replexica. The Y Combinator page lists 7 people and says the company raised US$4.2M, from Y Combinator, Initialized Capital and the founders of Supabase and Dependabot.

No source gives a revenue figure, a customer count or a date for the US$4.2M round, so this story is grade E. The headline is a traction fact: 5.4 thousand stars on the GitHub repository, read on 12 November 2026. The pricing page lists a Production plan at US$99 a month with a sign-up button, and the company's own customer stories name seven customers. No source states that a customer has paid.

## Why did Lingo.dev work?

### The founders rebuilt the product around a different buyer

The Y Combinator page says the first product translated software with AI on every commit. The founders write that this loop is about one percent of localization work. They say they rebuilt the company around localization managers and engineers, who answer for languages they cannot read.

### A free open-source command line tool connects to the paid engines

The code is on GitHub under the Apache-2.0 license, with 5.4 thousand stars. The company says its tool runs more than 10,000 times a week. The same tool now connects to the paid engines. No source says how many users moved to a paid plan.

### The price list passes model costs through without markup

The pricing page says the language model price passes through with no markup. The company charges US$2 per million tokens of its own infrastructure and a base of US$99 a month. The Sandbox plan has no base price, which lets a team test an engine first.

## How it was built

These details come from the company's own pages, its public code and the founder's blog. They are grade C.

- The site runs on Cloudflare Workers, with React, TanStack Router and shadcn/ui, per the humans.txt file. The careers page adds Effect.ts.
- An engine lets the team pick any model from the OpenRouter catalog. Each language pair gets a ranked fallback list, per the founder's v1.0 post.
- AI reviewers score each translation by dimension. An independent model scores the output, and the v1.0 post says this removes self-assessment bias.
- The command line tool needs Node.js 22 or newer. It reads 18 file formats, including JSON, Markdown and Android and Xcode strings, per the repository page.
- Releases are made by the github-actions account on the public repository, which lists 96 pages of releases.
- The careers page says the team uses Claude Code, MCP servers and AI agents every day to write code and review pull requests.

Sources: [5, 6, 9, 10, 16]

## Who tried this before Lingo.dev, and why did they fail?

Three companies in our database of failed startups promised to remove manual work from a developer's or a business's daily task. The values below are from that database and are not independently verified. The TurboTranslations record is written with "likely" and "probably".

The failed startups come from our database of dead startups, retold here in our own words; Its entries are AI-assisted summaries of public sources, so they carry no evidence grade.

### TurboTranslations (2014 to 2023; funding US$150K; cause: Technology change)

- Promise: A marketplace of freelance translators with workflow tools, as a cheaper alternative to translation agencies.
- Why it died: The record says a human-powered marketplace could not stand against machine translation. It does not give a firm date or a founder.
- Record: 

### Kite (2014 to 2024; funding US$21M; cause: Timing)

- Promise: AI code completion inside the editor, years before GitHub Copilot.
- Why it died: The record says Kite was too early to a market that later grew, and that it made monetization mistakes.
- Record: 

### CodeSee (2020 to 2024; funding US$10M; cause: Weak need)

- Promise: Automatic maps of a codebase, so that developers can understand it faster.
- Why it died: The record says the product was a vitamin where the market wanted a painkiller, and that its value was hard to measure.
- Record: 

## What changed

TurboTranslations sold human translators through a marketplace, and the record says machine translation replaced that work. Kite and CodeSee sold developer tools whose value was hard to price. The records do not say that these were the only causes.

Lingo.dev, by its pricing page, sells usage of a language model and passes the model cost through. It also publishes a free tool that developers can test before they pay. Whether the Production plan earns enough is not shown by any source read.

## Can one person copy Lingo.dev now?

**Verdict: Partly: the structure can be copied, the credibility cannot.**

The sources show a free open-source tool, a free sandbox and a published usage price. A new team could copy that structure. The company also shows named customers and a Y Combinator backing that a new team would not have.

1. Release a free command line tool that solves one task in a developer's workflow.
2. Put a paid engine behind the tool, and bill usage with the model cost passed through.
3. Publish the price list and a free sandbox plan, so a team can test before it pays.
4. Write a customer story for each early customer, with a quotation the customer approves.

**What is still open.** Other text tasks that engineering teams repeat on every release: release notes, documentation in many languages, support articles, email templates.

## How much revenue does Lingo.dev make? The numbers, graded

A two-founder start in December 2023, an open-source tool with 5.4 thousand GitHub stars, a published pay-as-you-go price list and no revenue figure

| Fact | Value | Grade | Note | Sources |
|---|---|---|---|---|
| Founders named by Y Combinator | Max Prilutskiy (CEO) and Veronica Prilutskaya (CPO) | C | The Y Combinator company page lists both as founders. The launch post says the two "met eight years ago at work". | [3, 4] |
| Start of the company | December 2023 | C | The Y Combinator page says "Founded in December 2023, after winning an AI product competition at Cornell Tech". Its fact box says "Founded: 2024". The careers page says the start was at a hackathon. | [3, 5] |
| Earlier name | Replexica | C | The footers and the terms name "Lingo.dev (Replexica, Inc)". GitHub packages were published as replexica from March 2024. The first lingo.dev release, version 0.70.1, is dated 27 January 2025. No page states the date of the rename. | [6, 8, 10, 11, 19] |
| First public release of the open-source tool | 20 March 2024 | C | The first GitHub release in the list is @replexica/compiler 0.0.2 of 20 March 2024. The command line tool replexica 0.18.0 follows on 28 March 2024. | [10, 11] |
| GitHub traction, 12 November 2026 | 5.4 thousand stars, 813 forks, Apache-2.0 license | C | Read on the repository page. The company's careers page says "more than 5,000 GitHub stars" and a command line tool that runs more than 10,000 times a week. | [9, 5] |
| Team size | 7 people | C | The Y Combinator page says "Team Size: 7" and has no date. The careers page says "lean, international, remote team" without a number. | [3, 5] |
| Funding stated by the company | US$4.2M | C | The company says it raised it from Y Combinator, Initialized Capital and the founders of Supabase and Dependabot. No date or split is given. A TechCrunch article of 18 February 2025 is listed on the Y Combinator page and was not opened. | [3, 4, 18] |
| Production plan price | US$99 a month base plus usage | C | The company's pricing page lists it with a "Set up Lingo.dev" button that points to a sign-up page. It lists credits with automatic top-up as the billing method. | [2] |
| Terms of service on fees | custom quotes | C | The terms, last updated 7 May 2026, say fees are flexible and quoted for each project. This differs from the public price list. | [8, 2] |
| Customers named by the company | SoSafe, Cal.com, Jarvi, Laurel, Papermark, Scribe, Truely | C | The company's customer stories, dated 29 and 30 January 2025 and 5 and 25 June 2026. A Laurel manager is quoted there saying "The enterprise pricing was fair". | [12, 13, 14] |
| Time from first release to the November 2026 status | 31 months | calc | Calculated: 20 March 2024 to 12 November 2026. | [10, 9] |

How to read this table. Grade C is the company's own statement on its own page, or a public record that the company keeps. A "calc" value was computed on this page. No value is grade A or B.

## Pricing

Lingo.dev prices read from the company's pricing page on 12 November 2026 (grade C)

| Plan | Per month, billed yearly (US$) | Per month, billed monthly (US$) | Limit |
|---|---|---|---|
| Sandbox |  | 0 | 100K tokens a day; 7 days of data retention; community support |
| Production |  | 99 | 5M tokens a day; 30 days of data retention; email support |
| Enterprise |  |  | Custom price; annual contract; human review, SSO, 99.99% uptime SLA |

The page says the bill counts processed translations and AI review runs, and that the language model price passes through with no markup. Billing is by credits with automatic top-up. The Sandbox plan has no base price. The Production plan lists a base price of US$99 a month. It adds US$0.50 per engine a month, US$2 per million tokens of Lingo.dev infrastructure and US$0.01 per AI review run.

## When did Lingo.dev launch, and how did it grow? Timeline

From a hackathon in December 2023 to a US$99 monthly plan in November 2026, as the company's pages and GitHub show it. Each entry carries its grade.

- **December 2023** (grade C [3, 5]): The company says it began at a hackathon at Cornell Tech, and that the project won best dev tool.
- **20 March 2024** (grade C [10, 11]): The first GitHub release appears, under the name Replexica. The command line tool replexica 0.18.0 follows on 28 March.
- **10 October 2024** (grade C [4]): The data of the Launch YC post gives this creation date. Its text was updated on 12 November 2026 and now names SOC 2 Type II and 300 million words.
- **27 January 2025** (grade C [11, 13, 19]): The first release under the name lingo.dev, version 0.70.1, appears on GitHub. The company's customer stories on Cal.com, Papermark and Jarvi are dated 29 January 2025.
- **15 March 2026** (grade C [16]): The founder's blog post introduces Lingo.dev v1.0, with engines, glossaries and AI reviewers that score each translation.
- **12 November 2026** (grade C [2, 9]): The pricing page lists Production at US$99 a month. The GitHub repository shows 5.4 thousand stars.

## What could go wrong for Lingo.dev?

- **What is not verified.** No revenue figure, customer count or round date was found. The Y Combinator page, the launch post, the pricing page, the customer stories and GitHub were read. The TrustMRR slug list holds no Lingo.dev entry. The US$4.2M, the team of 7 and the start in December 2023 are the company's own statements. The TechCrunch article of 18 February 2025 could not be opened under the pipeline's rules. No source states that a customer has paid. The customer stories are the company's own pages.
- **Logos, counters and badges are unsourced.** The home page shows a customer logo list with names that have no customer story: Mistral AI, Solana, freenet, Maze, Formbricks, Opus, Tulip and ImagenAI. Only Mistral AI and Solana are also named on the Y Combinator page. The counters "300M+ words processed", "Languages 100+" and "Enterprise uptime SLA 99.99%" have no source. The footer shows SOC 2 Type II, CCPA and GDPR with no report. The nine named quotations on the home page each match a customer story.
- **The terms and the price list disagree.** The terms of service, last updated 7 May 2026, say fees follow a custom quote and that payment terms come with that quote. The pricing page lists a Production plan at US$99 a month and a sign-up button. The documentation lists a payment error that asks the customer to top up the balance. A Wayback copy of the pricing page from 9 May 2026 already lists the US$99 plan, with an "Upgrade to Production" button. The two pages were not reconciled by any source, and no purchase was tested.
- **Earlier name and earlier work of the founders.** The company's legal name in the footers is Replexica, Inc. No page gives the date of the rename. The GitHub tags carry both names for versions 0.70.1 and 0.71.0. The lingo.dev releases of those versions are dated 27 and 29 January 2025. The launch post also says the founders once bootstrapped a software product with customers in over 100 countries. That product is not named, and no source dates it.

## Sources

1. Lingo.dev: Home page, read 12 November 2026 — https://lingo.dev/en (grade C). Read in full. Source for the logo list, the counters, the nine named quotations and the product claims.
2. Lingo.dev: Pricing, read 12 November 2026 — https://lingo.dev/en/pricing (grade C). Read in full. Source for the plans, the usage prices, the billing method and the sign-up button.
3. Y Combinator: Lingo.dev company page — https://www.ycombinator.com/companies/lingodotdev (grade C). Read in full on 12 November 2026. Source for the founders, the history, the team size and the US$4.2M statement.
4. Launch YC post: Lingo.dev, The Localization Engineering Platform — https://www.ycombinator.com/launches/M1p-lingo-dev-the-localization-engineering-platform (grade C). Read in full. Source for the post's creation date, 10 October 2024, the founders' background and the funding statement.
5. Lingo.dev: Careers — https://lingo.dev/en/careers (grade C). Read in full on 12 November 2026. Source for the hackathon start, the GitHub and command line numbers and the team's tools.
6. Lingo.dev: humans.txt — https://lingo.dev/humans.txt (grade C). Read in full. Source for the name Replexica, Inc and the site's technology.
7. Lingo.dev: Privacy Policy (last updated 7 May 2026) — https://lingo.dev/en/legal/privacy (grade C). Read in full. Source for the name Replexica Inc. and the age statement: not intended for children under 13.
8. Lingo.dev: Terms of Service (last updated 7 May 2026) — https://lingo.dev/en/legal/terms (grade C). Read in full. Source for the name Replexica Inc. and the fees section.
9. GitHub: lingodotdev/lingo.dev — https://github.com/lingodotdev/lingo.dev (grade C). Read in full on 12 November 2026. Source for the stars, the forks, the license and the readme.
10. GitHub: releases of lingodotdev/lingo.dev, pages 96 and 95 — https://github.com/lingodotdev/lingo.dev/releases?page=96 (grade C). Read pages 96 and 95, the oldest. Source for the first release date, 20 March 2024, and the replexica 0.18.0 date.
11. GitHub: release lingo.dev@0.70.1 — https://github.com/lingodotdev/lingo.dev/releases/tag/lingo.dev%400.70.1 (grade C). Read in full. Source for the first release under the lingo.dev name, 27 January 2025. The release lingo.dev@0.71.0 of 29 January 2025 was also read.
12. Lingo.dev: Customer stories — https://lingo.dev/en/customers (grade C). Read in full. Source for the list of seven customer stories.
13. Lingo.dev: How Cal.com Automated Localization for 36 Languages (29 January 2025) — https://lingo.dev/en/customers/cal-com (grade C). Read in full. Source for the date and a quotation of the Head of Engineering of Cal.com.
14. Lingo.dev: Laurel customer story (5 June 2026) — https://lingo.dev/en/customers/laurel (grade C). Read in full. Source for the quotation that mentions the enterprise pricing.
15. Lingo.dev documentation: Out of credits error — https://lingo.dev/en/docs/api/errors/credit-limit-reached (grade C). Read in full. Source for the credit balance and the automatic top-up.
16. Lingo.dev blog, 15 March 2026: Introducing Lingo.dev v1.0 — https://lingo.dev/en/blog/introducing-lingodotdev-v1 (grade C). Read in full. Source for the engine, the model catalog and the AI reviewers.
17. Database of failed startups, local export — /method/#dead (grade C). Record pages read on the website on 12 November 2026. AI-written summaries, not independently verified. Source for the failed predecessors.
18. TechCrunch, 18 February 2025: Lingo.dev is an app localization engine for developers — https://techcrunch.com/2025/02/18/lingo-dev-is-an-app-localization-engine-for-developers/ (grade C). Could not open: TechCrunch disallows the pipeline's agent. The title and date come from the Y Combinator page. Not used for any fact.
19. GitHub API: tags of lingodotdev/lingo.dev that begin with lingo.dev@0. or replexica@0.7 — https://api.github.com/repos/lingodotdev/lingo.dev/git/matching-refs/tags/lingo.dev@0.?per_page=100 (grade C). Read in full on 12 November 2026. The lowest lingo.dev tag is 0.70.1. Replexica tags exist for versions 0.70.0, 0.70.1, 0.71.0 and 0.71.1.
20. Internet Archive: Lingo.dev pricing page, copy of 9 May 2026 — https://web.archive.org/web/20260509232558/https://lingo.dev/en/pricing (grade C). Read in full. Source for the US$99 Production plan and the "Upgrade to Production" button on that date.

Contact: aiolum@livyden.com. Run Lingo.dev? Send corrections or a verified figure to aiolum@livyden.com (subject: Correction: Lingo.dev).