Read Frog: A Browser Extension That Turns Foreign-Language Pages into Side-by-Side Translations for Learners
QiaoLink Rating · Public Report
The QL Score is shown as a range because the current evidence does not allow us to pin it to a single number. The ends of the range are rounded to whole numbers. The rating is set by comparing the midpoint of the range (65.0) against fixed thresholds; the midpoint is calculated from the unrounded raw scores. The midpoint is only used to assign the rating band; it is not a "true, precise score".
Current recommendation
If you often read foreign-language pages on a computer and want to pick up the language along the way: fine to install and try. The free version needs no account and no API key; once installed, it shows each page with the original and the translation side by side.
If you only occasionally need to understand a foreign page: your browser's built-in translation is enough; there's no need to install anything.
If you use Chrome or Edge: after installing, consider turning off the "Help improve user experience" setting. It is on by default and tells the developer which websites you used which features on (not what the pages say).
If you work on sensitive pages such as internal company systems, online banking or email: don't turn on full-page or automatic translation there; the page text is sent to Google, Microsoft or whichever AI service you choose.
If you mainly use a phone or Safari: it won't work for you; it supports only Chrome, Edge and Firefox on computers.
Key Rating Drivers
A lot works for free: side-by-side pages, translating selected text and dual-language video subtitles cost nothing, and word lookups come with a small free AI allowance. Paid plans start at the equivalent of $2.50 a month billed annually.
Word lookups, sentence breakdowns, a word list and review are features that browsers' built-in translation doesn't have.
Translation quality hasn't been independently reviewed yet. But some users have already reported that, under the same conditions, it is slower than Immersive Translate and misses parts of some pages; the positive store reviews are shaped by the extension's own review prompts and can only be used for reference.
The default free translation relies on Google and Microsoft services that come with no service commitment. This year the Microsoft one broke for about 10 days: everyone using Microsoft translation was affected, and new users who couldn't reach Google had no working translation at all.
What it is
Read Frog is a translation and language-learning tool that runs in your computer's web browser. Once installed, it can:
Show pages side by side: put a translation under each paragraph of the original, or show the translation only; you can set certain sites to translate automatically when you open them.
Translate selections and look up words: translate any text you select; select a word and click "Dictionary" to get its pronunciation, part of speech and meaning in context; select a long sentence and click "Sentence Analysis" to see it broken down. It can also read text aloud.
Show dual-language video subtitles: on YouTube, Netflix and X.
Translate what you type: type in your own language, press the space bar three times, and it translates into the foreign language.
Keep a word list and review it: save words you looked up with one click and review them on a schedule that, according to the developer, brings each one back just before you'd forget it. This part needs an account.
The extension's source code is open source on GitHub (GPL-3.0). It is run by FEELIO TECHNOLOGIES LTD., a Canadian company, and its terms of service are governed by Canadian law. Note that it is not 100% open source: the extension includes a layout component the developer keeps proprietary (used for the AI lookup cards), and the developer's server code is not public. The core page translation doesn't depend on either.
Do you need your own AI key? What does it cost?
You can use it without one. Read Frog's translations can come from three places:
After installation, page translation uses Google Translate by default (or Microsoft Translator on networks that can't reach Google); "Dictionary" and "Sentence Analysis" use the Built-in AI by default.
Roughly what your own key costs (QiaoLink estimate):
Take Gemini 3.5 Flash-Lite, which Google describes as suited to translation: its official price is $0.30 per million input tokens and $2.50 per million output tokens (as of 2026-11-01).
Translating an article of about 2,000 English words into Chinese, assuming about 3,000 input tokens and 3,000 output tokens, costs less than one cent.
Reading three such articles a day comes to about $0.80 a month.
A pricier model can multiply that cost. Turning on "context-aware translation," which sends the whole article along with each request, also raises it noticeably (it is off by default).
There are free options too: a local model, or Gemini's free tier, though Google's price list states that free-tier data is used to improve Google's products.
The supported AI services also include ones from Chinese companies, such as DeepSeek, Alibaba Cloud, Volcengine and SiliconFlow. None of them is used by default; it's up to you whether to choose one.
Pricing
(Official pricing and comparison pages, verified on 2026-11-01; one subscription per person)
Monthly prices: the pricing page shows annual prices ($30 a year for Pro, $70 a year for Ultra); the monthly prices of $3 and $7 appear only on the website's comparison page with Immersive Translate. The crossed-out prices on the pricing page ($36 and $84) are exactly 12 times the monthly prices, so the two pages agree. The Chinese pricing page shows yuan: ¥198 a year for Pro and ¥498 a year for Ultra.
Early-bird pricing: the pricing page marks both Pro and Ultra as a "Limited-time early bird special," without saying when it ends, so prices may change.
"GPT-6 Luna": the pricing page says Ultra's Advanced Built-in AI is "powered by GPT-6 Luna." That is a published OpenAI model, which OpenAI positions as a cost-sensitive option for high-volume use; QiaoLink can't verify whether Read Frog actually uses it.
You can cancel at any time and keep access until the end of the billing period; you can ask for a refund by email within 14 days of purchase.
Where the official pages disagree: the terms of service (2026-07-07) say the free plan allows 50 notes and that cards can be generated and reviewed without a paid plan; the pricing page (2026-11-01) says 10 notes and "Limited flashcard review" on the free plan. Go by what your account shows.
Your own key doesn't need a subscription: page, selection and subtitle translation with your own key are free and unlimited. A subscription mainly buys you not having to manage a key, plus PDF translation and AI-generated subtitles.
Where your page content goes
When you translate: the page text you translate is sent to the translation service you chose (Google or Microsoft by default). That's true of every online translation tool, but be aware: if you turn on full-page or automatic translation on internal company systems, online banking or email, that text is sent too.
What goes to the developer:
AI features such as word lookups: "Dictionary" and "Sentence Analysis" use the Built-in AI by default, sending the text you selected and the paragraph around it to Read Frog's servers, which pass it on to Microsoft's Azure OpenAI; another built-in feature, "Improve Writing," also sends the page title and full web address. If you switch these to your own AI service, the content goes to that service instead.
AI-generated subtitles (paid plans): the video's web address and length are sent; the developer's servers fetch the audio, transcribe it with Microsoft's speech service, and store the subtitles along with the video's address and title.
Word list: what you save (usually the selected text and the AI's explanation) is stored on the developer's servers; the developer says it doesn't add the address of the page you were reading.
The privacy policy says the servers record how much you used, not the text you sent; once you sign in, those usage records are linked to your account. That is the developer's own statement; QiaoLink can't verify it from outside, because the server code isn't public.
Usage statistics: on by default in the Chrome and Edge versions, off by default in Firefox. They report which website you were on (the domain only, such as en.wikipedia.org), which feature you used and where you started it, whether it worked, how long it took, how many characters were translated, which languages were involved, which type of translation service you used, plus a random installation ID and browser, system, language and time-zone details. Judging from the source code, they don't send page content, the text you selected, translations, full web addresses, page titles or your keys, which matches the privacy policy. To turn them off: Settings → Preferences → User experience → turn off "Help improve user experience."
One inconsistency: the privacy section of the Chrome Web Store listing says "The developer has disclosed that it will not collect or use your data," while Read Frog's own privacy policy says usage statistics are collected by default. Rely on the privacy policy and the source code.
Your keys and settings: stored in your own browser and not uploaded. Only if you turn on "sync to Google Drive" yourself does the whole configuration, keys included, go to your own Google Drive.
Browser permissions it asks for: read and change data on all the websites you visit, read your tabs, access cookies, run scripts on pages, sign-in authorization and more. A page translator has to work on any site, so most of these are necessary, but they are broad. Install only from the official Chrome, Edge or Firefox stores; the GitHub project page also lists a third-party mirror download for users in mainland China, which is not an official store.
If you want to stop: just uninstall it from your browser, and the data stored locally goes with it. If you created an account, you can delete it along with your notes in the account settings on the website. When you uninstall, the browser opens a survey page whose web address includes the extension version and your browser and system details.
How well does it work?
There is no independent review yet. QiaoLink did not install it (this rating did not involve installing the extension); below is what we could check against public sources:
Plenty of people use it: 60,000 users and 4.8 stars (128 ratings) on the Chrome Web Store, about 35,000 installs and 4.5 stars (12 ratings) on Edge, and about 1,800 daily users and 4.9 stars (22 ratings) on Firefox. The developer says it has been installed more than 240,000 times in total; that figure comes from the developer.
Why the store ratings are for reference only:
Since September 16, 2026, the extension invites users to leave a review after they have used it successfully on three separate days. The developer's code notes say users whose translations keep failing are deliberately not asked. This is common practice, but it may tilt ratings toward the positive.
Until October 19, users who installed from the Edge store were also sent to the Chrome Web Store to leave their rating.
Chrome ratings: 82 on August 4, 95 on September 24 and 128 on November 1, growing noticeably faster after the review prompt arrived. The Chrome user count was 90,000 on September 24 and 60,000 on November 1, for reasons that aren't known.
Of the 22 Firefox ratings, 14 come from accounts that have rated nothing else on the Firefox store, and some reviews use almost the same wording (translated from Chinese: "came over from V2EX / linux.do, waited ages for it to launch"), mostly from Chinese tech-community users showing support when it launched there in March 2026.
On X, there are also three recommendation posts with almost identical wording; it isn't known who was behind them, and QiaoLink did not treat them as user reviews.
These are facts only. QiaoLink found no evidence of fake reviews, but these ratings and short reviews don't show that it works well.
User feedback we could check at the source (GitHub):
One user, using the same Google translation service in both, wrote (translated from Chinese) that "Immersive Translate is fast, while Read Frog is a few seconds slower or even fails"; another said it was "still slow compared with Immersive Translate, which is instant," though after switching to Google Translate and adjusting settings they found it "acceptable."
One user found text left untranslated on a website, while Immersive Translate with the same model handled the page fine; within minutes the developer replied that a newer version had already fixed it.
A Firefox user said the browser became sluggish and that it was "getting more and more bloated"; earlier there were also reports of long pages freezing and benchmark scores dropping sharply, most of which have been fixed.
A three-star Chrome review simply said it "often crashes" (translated from Chinese); the developer replied the same day asking which service was failing.
On the positive side, a Firefox user wrote (translated from Chinese) that it "replaces the increasingly bloated Immersive Translate and feels even better to use," while another said "performance and details still need polishing"; one noted it doesn't work in Firefox for Android.
Known problems: GitHub still lists some long-unfixed problems on particular websites. Notion pages barely translate, comment sections on some news sites are skipped, it clashes with some forum reply boxes and dark-mode extensions, and YouTube subtitles occasionally fall out of sync with the audio. On such sites, you can turn translation off for that site or try a different translation service.
QiaoLink's view:
Where evidence is missing: there is no independent review yet, so it isn't possible to say how good its translations are overall. That is a lack of evidence, not proof of poor quality. How good the translation itself is depends mainly on the service you choose.
Negative feedback that already exists: text missed or layouts broken on particular websites, some unfixed for about a year; and several users found it slower than Immersive Translate under the same conditions.
Plenty of people use it on everyday websites; apart from this year's Microsoft translation outage (see "How well is it maintained?"), QiaoLink found no reports of it failing widely; some users have switched to it from Immersive Translate. But there is no evidence that it beats comparable tools.
How well is it maintained?
(Public GitHub data, 2026-11-01)
Frequent updates: 38 releases and 262 code changes in the last three months; 65 contributors; automated tests.
Quick replies: of the 53 issues outside users raised on GitHub from August to October 2026, 40 got a reply from the developers, with a median of about 8 hours to the first reply. Most of the 62 issues still open are feature requests, marked as on hold or inactive.
A small core team: about 70% of code changes in the last three months came from two people, backed by a company.
An outage of about 10 days this year:
What happened: Microsoft shut down the free translation entry point the extension used. By the developer's own account, Microsoft translation in the extension stopped working entirely from around July 28, 2026; between August 3 and 5, several other translation tools reported the same problem.
Who was affected: everyone using Microsoft translation. The developer says new users who couldn't reach Google had no working translation at all during that time. According to the extension's update history, users who installed it between May 16 and July 25, 2026 and kept the default settings were also on Microsoft translation (QiaoLink's inference from the update history; no figures on how many people were affected are public).
How it was fixed: the new version of August 7 did not restore the original entry point; it switched to a different Microsoft translation entry point that needs no sign-in. It isn't known when the Chrome and Edge stores finished rolling it out.
What was lost: the new entry point can't keep a page's formatting, so Microsoft translation is no longer offered for full-page translation in "translation only" mode; settings that used that combination were switched automatically to Google Translate (or back to side-by-side mode if Google wasn't set up). Subtitles, selected text and typing translation can still use Microsoft.
It shows that the default free translation relies on Google and Microsoft services with no commitment behind them, and they could change again.
The extension updates automatically through the store, so you don't need to maintain anything yourself.
Is it worth switching from what you use now?
Verified on 2026-11-01. The Immersive Translate column comes from its own website, official documentation and its official Chrome Web Store description; its website loads the price table live in the page, and we could not obtain specific prices this time. QiaoLink has not tested Immersive Translate.
Compared with built-in browser translation: if you're trying to learn the language, it adds a side-by-side view, word lookups and review; if you just want to understand the content, built-in translation is simpler.
Compared with Immersive Translate: both offer side-by-side pages and subtitles. Read Frog's selected-text translation is available on the free plan, its extension code is open source, and it adds sentence breakdowns and a word list with review; Immersive Translate supports phones and Safari, translates ebooks and images, and several users found it faster under the same conditions. No independent comparison shows which one translates better, and since Immersive Translate's paid prices couldn't be obtained from its website this time, we haven't compared prices.
Compared with DeepL: DeepL is mainly a translation service (its lowest Pro tier works out to about €7.49 a month billed annually), and it can also be used as one of Read Frog's translation sources, so it isn't an either-or choice.
Who it suits, and who it does not
Suits
People who often read foreign-language web pages or watch YouTube on a computer and want to pick up the language along the way.
People who want free side-by-side reading.
People willing to add their own AI key and keep costs to cents or a few dollars a month.
People who care about open-source software and want to be able to see what it does to a page.
Less suitable for
People who mainly use a phone or Safari.
People who only occasionally need to understand a page.
People who often work on sensitive pages and don't want to spend time on settings.
Organizations that need a service commitment: the default translation relies on free services that could change at any time.
Practical advice after installing
On Chrome or Edge, go to Settings → Preferences → User experience and turn off "Help improve user experience."
In the site settings, exclude internal company systems, online banking and email from automatic translation.
If a site doesn't translate fully, try a different translation service first.
If you want better translations, then consider adding your own AI key or subscribing to Pro; before subscribing, try the lookup features with the free allowance.
Install only from the official stores.
Why this rating
The benefits are documented: side-by-side reading is free; word lookups, sentence breakdowns, a word list and review are features built-in browser translation doesn't have; paid plans start at the equivalent of $2.50 a month billed annually.
It is actively maintained: frequent updates, quick replies and automated tests, though it relies mainly on two people.
On quality: first, evidence is missing: there is no independent review, and positive store reviews are shaped by how reviews are requested. Second, there is negative feedback: the user comparisons we could check mostly say it is slower than Immersive Translate or misses parts of some pages, and translation gaps on some websites have gone unfixed for a long time.
Reliability has had clear problems: the default Microsoft translation broke for about 10 days this year, leaving new users who couldn't reach Google without translation; there were also reports of it slowing the browser down, most of which have been fixed.
The added value is real but not proven better than comparable tools: Immersive Translate has the core side-by-side features too, and there are several other open-source alternatives.
There are a few minor privacy points: usage statistics are on by default in Chrome and Edge, the store listing doesn't match the privacy policy, the permissions are broad, and word lookups go through the developer's servers by default. But page content isn't sent to the developer by default, and the statistics are easy to turn off.
What could lead to an upgrade: if an independent comparison shows the current version translates and handles web pages better than Immersive Translate, there would be grounds for an upgrade.
Where the evidence comes from
Directly verified by QiaoLink (E2):
the extension's source code on GitHub (version of 2026-10-31): permissions, default settings, usage statistics and translation services;
GitHub maintenance data: releases, code changes, issue handling and reply times, the changelog, the fix for the Microsoft translation outage, and the code notes for the review prompt;
the official pricing page, comparison page, privacy policy (2026-10-19 version), terms of service (2026-07-07 version) and documentation;
the Chrome, Edge and Firefox extension store listings and figures, plus earlier versions of the Chrome listing in web archive snapshots;
the browsers' official help pages on built-in translation; Immersive Translate's website, official documentation and official Chrome Web Store description; DeepL's prices; Google's official Gemini price list (used for the cost estimate); OpenAI's and Microsoft Azure's model pages.
Independent external evidence (E3):
users' problem reports on GitHub, including comparisons with Immersive Translate under the same conditions;
one third-party blog post describing four open-source translation extensions (August 2026);
reports from other translation tools of the same Microsoft outage at the same time;
user ratings and reviews in the three extension stores (for reference only).
Self-reported by the developer (E1):
total install numbers;
the statement that the servers record usage but not text;
the statement that Ultra uses "GPT-6 Luna";
the developer's comparison with Immersive Translate, which this report does not rely on.
Still missing (E0):
an independent review of translation quality and how well it handles web pages, and a systematic comparison with Immersive Translate and built-in browser translation;
detailed long-term user feedback;
exactly when the Microsoft outage began, how many users were affected, and when the stores finished rolling out the fix;
detailed feedback from English-speaking and long-term users;
Immersive Translate's specific prices on its website, and whether its free plan includes selected-text translation.
Verification limits: we did not install the extension, create an account, enter a key or pay for this rating. How well it works comes from public feedback and the source code and has not been directly verified by QiaoLink. The cost of using your own key is QiaoLink's estimate based on published prices and stated assumptions; what you actually pay depends on the service you choose and how much you read.
QiaoLink did not install the extension, sign up, pay or contact the developer in the course of this rating. Evidence is current as of 2026-11-01.