--- title: "Reading apps that explain a passage beside the text (2026)" description: "Seven reading apps compared on explaining a hard word or passage without leaving the page: what you can select, where it opens, which files, and the cost." canonical: "https://omphalis.ai/blog/reading-apps-that-explain-a-passage-beside-the-text-2026" source: "https://omphalis.ai/blog/reading-apps-that-explain-a-passage-beside-the-text-2026" --- # Reading apps that explain a passage beside the text (2026) September 29, 2026 · 13 min read > **Quick summary:** For difficult reading, Omphalis ranks first: explanations (define, source, expand) open beside the text on every plan, and it works the same on articles, PDFs (on paid plans), and transcripts. Readwise Reader suits heavy highlighters who want their own prompts, and Gloss suits iPhone and iPad readers who want margin notes. For a second language, LinguaRead, Okuzeka, and Kindle's Word Wise explain a word in its sentence. Hypothesis is the pick when you want explanations from other people rather than software. *We make Omphalis, so weigh its place on this list accordingly. Every other entry was checked against the vendor's own pages on September 29, 2026; prices and features change, so confirm before you pay.* This guide is for people reading material that pushes back: the methods section of a paper, a dense essay, a novel in the language you are learning. You reach a term or a sentence you do not follow, and you want it explained beside the text, without a new tab that costs you your place. We compared seven apps on that moment: what you can select, where the explanation appears, which files it works on, who or what writes it, and the cost. Competitor facts come from each vendor's own site, help docs, or app store listing. ## Quick comparison | Tool | Best for | What gets explained | Where it appears | Price | | --- | --- | --- | --- | --- | | [Omphalis](https://omphalis.ai/) | Studying difficult articles, papers, and talks | Marked terms and passages, plus any phrase | Beside the text | Free plan; Pro $9/month | | [Readwise Reader](https://readwise.io/read) | Heavy highlighters | Any selection, or the whole document | Chat sidebar; bottom panel on mobile | 30-day trial, then $9.99/month billed annually | | [Gloss](https://apps.apple.com/us/app/gloss-annotated-reader/id6782358267) | DRM-free books on iPhone and iPad | Any highlighted passage | A margin note | 10 free glosses; $5.99/month | | [Kindle](https://www.amazon.com/kindle-dbs/fd/kcp) | Kindle Store books | Words, characters, places, terms | Lookup cards; hints above words | Free apps; you buy books | | [Okuzeka](https://okuzeka.com/) | Second-language reading in 180+ languages | A tapped word or idiom | In the book | Free (20 lookups/month); $9.99/month | | [LinguaRead](https://linguaread.dev/) | Language learners on iPhone and iPad | A tapped word, with why | On the page | Free daily limit; $5.99/month | | [Hypothesis](https://web.hypothes.is/) | Classes reading the same text | What other readers annotated | A browser side panel | Free for personal use | ## What to look for **Where the explanation opens.** Beside the passage, you read it, glance back at the sentence, and carry on. A chat thread or new tab suits a real question but is costly for a quick check. **How much you can select.** Language learners mostly need a word or idiom explained in its sentence. A paper reader needs more: a caveat, a sentence, a paragraph that assumes something. Check whether the app explains passages or only words. **Whether it works on your own files.** Kindle's Word Wise and X-Ray, and Google Play Books' book insights, work only on enabled or select titles. If your hard reading is a journal PDF, confirm the app opens PDFs, and on which plan. **How it handles being wrong.** A confident wrong explanation of a key term does more harm than none. Prefer apps that mark only what they are confident about, admit limits, or show who wrote the note. **What the limits cost.** Many apps meter lookups per day or month, so match the limit to how often you get stuck. ### 1. [Omphalis](https://omphalis.ai/) Omphalis is a reading app for people studying or researching what they read. It turns articles, PDFs, EPUBs, Word documents, podcasts, and YouTube talks into one clean page and underlines the terms and passages worth explaining; open one and the explanation appears beside the text ([how it works](https://omphalis.ai/reading-comprehension)). **Highlights** - Define, source, and expand explanations open beside the text, on every plan - Select any phrase and open Learn more for a deeper explanation - Deliberately few marks: it underlines only what it is confident about - The same reader for articles, [PDFs](https://omphalis.ai/read/pdf), and transcripts, with a section map beside long pieces **Specs** - **Best for:** Studying or researching difficult articles, papers, and talks - **Formats:** Articles, PDFs, EPUBs, Word documents, podcasts, YouTube talks, newsletters, notes - **Platforms:** Web (the most complete), iOS, Android, Chrome and Firefox extensions; also inside ChatGPT and over MCP - **Price:** Free plan; Pro $9 a month or $90 a year; a 30-day trial of every feature, no card ([pricing](https://omphalis.ai/pricing)) **Pros** - Explanations on every plan, including Free - One reader for a paper, an essay, and a podcast episode on the same subject **Cons** - PDFs are read on paid plans and during the trial; Free keeps the file but does not turn it into a readable page - Free covers about 20 articles or 2 hours of podcasts a month - Newer and less established than Readwise or Kindle, and no desktop app Pick it if you study papers, essays, and talks and want the hard spots explained where they sit. ### 2. [Readwise Reader](https://readwise.io/read) Readwise Reader is a read-later and annotation app with Ghostreader built in. On web and desktop you select text and choose Chat about this (or press G), and the response appears in the chat in the right sidebar ([Ghostreader overview](https://docs.readwise.io/reader/guides/ghostreader/overview)). **Highlights** - Works on a selection or the whole document; for one to three words, presets include dictionary define and encyclopedia lookup - On mobile, [Quick Lookup](https://docs.readwise.io/reader/guides/ghostreader/quick-lookup) slides up a panel with Define, Lookup in context, and Translate - Edit the prompts or write your own ([Ghostreader FAQ](https://docs.readwise.io/reader/docs/faqs/ghostreader)) **Specs** - **Best for:** Heavy highlighters who want to shape the prompts themselves - **Formats:** Articles, PDFs, EPUBs, newsletters, RSS, YouTube transcripts - **Platforms:** Web, desktop, iOS, Android, and a browser extension - **Price:** Free for 30 days with no card, then a Readwise subscription at $9.99 a month billed annually or $12.99 billed monthly **Pros** - Desktop apps, and more control over how explanations are asked for than Omphalis offers - The Daily Review resurfaces your highlights with spaced repetition, which Omphalis does not do **Cons** - Needs a paid Readwise subscription once the trial ends - Quick Lookup is mobile only; on web and desktop, explanations come through the chat Pick it if your reading already runs through Readwise highlights. See also [Omphalis vs Readwise](https://omphalis.ai/vs/readwise). ### 3. [Gloss](https://apps.apple.com/us/app/gloss-annotated-reader/id6782358267) Gloss, from NYRAI LLC, is built around the margin note. Highlight a passage in a book, PDF, saved article, or your own notes, and a note explains it in what the [App Store listing](https://apps.apple.com/us/app/gloss-annotated-reader/id6782358267) calls a voice informed by the author's style. **Highlights** - Choose Gloss, Go deeper, Define, or Ask; notes appear in a side column on iPad or an anchored card on iPhone - Follow-up questions are answered beside the text, never in a chat window, the developer says - Reads DRM-free EPUBs, PDFs, and articles from a pasted link **Specs** - **Best for:** iPhone and iPad readers of DRM-free books and papers - **Formats:** DRM-free EPUB, PDF, articles, your own notes (not Kindle or Apple Books DRM files) - **Platforms:** iPhone, iPad, Apple silicon Macs (as an iPad app), Apple Vision - **Price:** Reading is free; the first 10 glosses are free, then $5.99 a month or $49.99 a year **Pros** - Explains any passage you highlight, in a note that stays beside it in the margin - Your files stay on your device; only the passage and a little surrounding text are sent **Cons** - Apple devices only - The listing says author "voices" are an interpretation, not the real author, and may be inaccurate Pick it if you read DRM-free books on an iPad and want a margin that answers back. ### 4. [Kindle](https://www.amazon.com/kindle-dbs/fd/kcp) Kindle builds explanations into the reading view. Amazon's [Kindle Paperwhite user guide](https://d1ergij2b6wmg5.cloudfront.net/kug/kindle_paperwhite_12th/v1/en-US/html/kug.html) describes Smart Lookup: select one or more words and cards may show X-Ray, Wikipedia, a dictionary definition, and translation. **Highlights** - Word Wise shows simple definitions above difficult words on many popular English-language titles; tap a word for definitions and synonyms - X-Ray shows all the passages that mention a character, place, topic, or term, on enabled books - [Recaps](https://www.amazon.com/gp/help/customer/display.html?nodeId=T7ct0DmE9emSHOIpu8) refresh your memory of thousands of best-selling English-language books in series, on US e-readers **Specs** - **Best for:** Kindle Store readers, including people learning English - **Formats:** Kindle books; Word Wise, X-Ray, and Recaps on enabled titles only - **Platforms:** Kindle e-readers, plus free apps for iOS, Android, Mac, and PC (features above are from the e-reader guide) - **Price:** The apps are free; you pay for books **Pros** - Word Wise hints appear before you ask, which is gentler than any lookup for a second-language reader - Vocabulary Builder turns looked-up words into flashcards, which Omphalis does not do **Cons** - Enabled titles only, and Amazon says X-Ray is not available in all countries - The guide describes word and topic lookups, not explanations of a whole passage Pick it if your difficult reading is Kindle books, especially English novels in a second language. ### 5. [Okuzeka](https://okuzeka.com/) Okuzeka is a tap-to-translate reader for second-language reading. On [Okuzeka's site](https://okuzeka.com/), tapping a word shows the meaning that fits its sentence, a translation, and a short usage note when needed, without opening a separate translator. **Highlights** - Treats idioms and multi-word expressions as one unit of meaning - The book's language and the explanation's language are set separately, across 180+ languages - Saved words become flashcards with a practice mode **Specs** - **Best for:** Books in a language you are learning, in almost any language pair - **Formats:** Your PDFs and EPUBs, plus books from its store - **Platforms:** Web, iOS, Android - **Price:** Free for 20 word queries a month and 2 uploaded books; Reader is $9.99 a month for 800 queries ([pricing](https://okuzeka.com/pricing)) **Pros** - Far wider language coverage than Omphalis, with explanations in your own language - Flashcards built from your lookups, which Omphalis does not make **Cons** - Explains words and phrases, not whole passages - 20 lookups a month go quickly on a hard book Pick it for a novel or textbook in a language you are still learning. ### 6. [LinguaRead](https://linguaread.dev/) LinguaRead is an iPhone and iPad reader for language learners from an indie developer. On [LinguaRead](https://linguaread.dev/), you tap a word to see what it means in this sentence, with a one-line note on why, and grammar when you want it. **Highlights** - Handles idioms, archaic words, and slang - Saved words keep their sentence; SM-2 spaced repetition, one deck per book, Anki or CSV export - 14 languages, including Spanish, French, Japanese, and Arabic **Specs** - **Best for:** Reading real books in the original on iPhone or iPad - **Formats:** DRM-free EPUB, plus a built-in library of free classics - **Platforms:** iPhone and iPad (iOS 17 or later); no Android yet - **Price:** Free with limited lookups per day; Plus is $5.99 a month or $49.99 a year **Pros** - The "why" note teaches the language, which Omphalis is not built to do - No account needed, and reading works offline **Cons** - Apple devices only, and the site describes EPUBs and classics, not PDFs or web articles Pick it to read a classic in the original and keep new words in their sentences. ### 7. [Hypothesis](https://web.hypothes.is/) Hypothesis is the exception here: the explanations beside the text come from people. On [Hypothesis](https://web.hypothes.is/), students, colleagues, or any group highlight and comment over web pages, online PDFs, and videos. **Highlights** - Select content and a window opens on the right with public or group annotations ([getting started](https://web.hypothes.is/start/)) - Reply to annotations and tag people into the discussion - Works inside Canvas, Blackboard, Moodle, and D2L, and on JSTOR articles **Specs** - **Best for:** Courses and reading groups working through the same text - **Formats:** Web pages, online PDFs, videos - **Platforms:** Chrome extension (also Brave, Vivaldi, and Edge); a bookmarklet for Firefox and Safari - **Price:** Free for personal use and collaboration; education plans priced per student per year ([pricing](https://web.hypothes.is/pricing-page/)) **Pros** - A person's explanation carries context software cannot, and you can reply to it - Free for personal use, including private groups **Cons** - Explanations exist only where someone has annotated; a new text may have none Pick it if you read with a class and want explanations from people who know the text. ## Which one should you pick? **You study papers, essays, and talks.** Omphalis. Explanations open beside the passage in every format you are likely to study. Try the trial on a real PDF, since PDFs need a paid plan afterwards. **You already highlight everything in Readwise.** Readwise Reader, for Ghostreader on any selection. **You read DRM-free books on an iPad.** Gloss, for a margin note on any passage. **You read in a second language.** LinguaRead on iPhone or iPad if your language is among its 14; Okuzeka for rarer pairs or Android; Kindle's Word Wise for English novels from the Kindle Store. **You read with a class.** Hypothesis, because its explanations come from the people reading with you. ## Frequently asked questions ### Who offers a reading app with explanations beside highlighted text? Several apps do. Omphalis opens explanations (define, source, expand) beside the text in articles, PDFs, and transcripts; Readwise Reader answers a selection through Ghostreader; Gloss writes a margin note for any highlighted passage on iPhone and iPad. For language learners, LinguaRead, Okuzeka, and Kindle's Word Wise explain words in place, and Hypothesis shows explanations written by other readers. ### Which reading app explains a difficult passage in a PDF without leaving the page? Omphalis and Gloss both open PDFs and explain a passage alongside the text. In Omphalis, PDFs are read on paid plans and during the 30-day trial; Gloss runs on iPhone and iPad. Readwise Reader also reads PDFs, and Readwise describes Ghostreader as working on whatever you are reading. ### What is the best app for reading a book in a foreign language with explanations? On iPhone and iPad, LinguaRead shows what a tapped word means in its sentence and why, then reviews saved words with spaced repetition. Okuzeka covers 180+ languages on web, iOS, and Android and reads your own PDFs and EPUBs. Kindle's Word Wise suits people learning English who read Kindle books. ### How does Readwise Reader's Ghostreader explain highlighted text? On web and desktop you select text and choose Chat about this, or press G, and the response appears in the chat sidebar, where you can follow up. On mobile, Quick Lookup opens a panel with Define, Lookup, and Translate for one to three selected words. ### Can you trust explanations generated by a reading app? Treat them as suggestions, not verdicts, and check anything that matters. Omphalis marks only what it is confident about rather than underlining everything, and Gloss says its author voices are an interpretation that may be inaccurate. For explanations from people instead, Hypothesis shows annotations written by other readers. ### Does Kindle explain words while you read? Yes. On Kindle e-readers, selecting a word shows cards that may include a dictionary definition, Wikipedia, X-Ray, and translation. Word Wise shows simple definitions above difficult words on many popular English-language titles, and X-Ray works on enabled books, though not in all countries. *Last updated: September 29, 2026* > Also read: [Reading comprehension in Omphalis](https://omphalis.ai/reading-comprehension), [Reading PDFs in Omphalis](https://omphalis.ai/read/pdf), and [Omphalis vs Readwise](https://omphalis.ai/vs/readwise) - [Reading Apps](https://omphalis.ai/blog/tag/Reading%20Apps) - [Reading Comprehension](https://omphalis.ai/blog/tag/Reading%20Comprehension) - [Annotation](https://omphalis.ai/blog/tag/Annotation) - [Language Learning](https://omphalis.ai/blog/tag/Language%20Learning) - [Study Tools](https://omphalis.ai/blog/tag/Study%20Tools) --- Listed on: [Featured on launched.tools REVIEWED ✓](https://launched.tools/tools/omphalis)