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Extract what the page is saying.
Distill what matters to the reader.

xTil reads any web page and writes the summary its genre deserves. Around twenty genres in all — a film hides spoilers, a paper extracts claims, a pull request weighs merge-readiness. Bring your own AI key. No backend, no proxy, no middleman.

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Quantum Computing Crosses Critical...
sciencedaily.com/quantum-computing-2024-breakthrough
Quantum computing circuit diagram

Quantum Computing Crosses Critical Error-Correction Threshold in 2024

Science Daily Dec 14, 2024 12 min read

Quantum computing uses qubits in superposition to perform calculations exponentially faster than classical bits. Unlike traditional binary bits that exist as either 0 or 1, qubits exploit the principles of quantum mechanics to represent both states simultaneously.

Current hardware from IBM (Condor, 1,121 qubits) and Google (Sycamore) has surpassed major milestones. However, the real bottleneck is error correction — noisy intermediate-scale quantum (NISQ) devices still produce too many errors for most practical applications.

The global quantum computing market is projected to reach $65 billion by 2030, driven by advances in superconducting circuits, trapped ions, and topological qubits. Governments and private investors are pouring capital into the sector at unprecedented rates.

Researchers at MIT and Caltech have demonstrated a novel approach to quantum error correction that reduces overhead by an order of magnitude, bringing practical quantum advantage significantly closer.

“We are now at the stage where quantum computers can do things that classical computers cannot,” said Dr. John Preskill of Caltech. The new technique uses a syndrome decoding method that can identify and correct errors faster than they accumulate.

The implications extend beyond pure computation. Quantum-safe cryptography, pharmaceutical drug discovery, climate modeling, and optimization problems in logistics could all benefit from fault-tolerant quantum machines within the next decade.

Industry analysts note that the transition from NISQ to fault-tolerant systems represents the most significant inflection point since the field’s inception. Microsoft’s topological qubit approach and IonQ’s trapped-ion systems offer alternative paths that may prove more scalable in the long run.

Meanwhile, China’s Jiuzhang photonic processor and Canada’s D-Wave annealing systems demonstrate that the race is not limited to superconducting approaches. Each platform carries distinct advantages for specific problem domains, from molecular simulation to financial optimization.

The road ahead remains challenging. Decoherence times, qubit connectivity, and the sheer engineering complexity of maintaining cryogenic temperatures near absolute zero continue to impose practical limits. Yet the pace of progress over the past 24 months has exceeded even the most optimistic projections from the field’s leading researchers.

xTil
ARTICLE GPT-4o 12 min read
Quantum computing circuit diagram
Quantum Computing Crosses Critical Error-Correction Threshold
Science Daily · Dec 14, 2024 · 2,847 words · 3 images
TL;DR
+×
Researchers have crossed the critical error-correction threshold for quantum computing, reducing overhead by 10x. IBM’s 1,121-qubit Condor and Google’s Sycamore demonstrate quantum advantage, with the market projected to hit $65B by 2030.
Key Takeaways
+×
1 Error correction breakthrough — MIT/Caltech reduced quantum error correction overhead by 10x, crossing a critical threshold.
2 Hardware milestones — IBM Condor reaches 1,121 qubits; Google Sycamore demonstrates quantum advantage.
3 Market growth — $65B projected by 2030 across superconducting, trapped-ion, and topological approaches.
Summary
+×
The quantum computing field reached a pivotal moment with a novel error-correction approach that dramatically reduces computational overhead.
Qubit Init Error Detect Syndrome Fix
Fact Check
+×
IBM Condor has 1,121 qubits — Verified. Announced Dec 2023.
$65B market by 2030 — Verified. Matches McKinsey & BCG estimates.
10x overhead reduction — Contested. Paper claims 8–12x depending on architecture.
Google Sycamore quantum advantage — Verified. Published in Nature 2019.
Notable Quotes
+×
“We are now at the stage where quantum computers can do things that classical computers cannot.”
— Dr. John Preskill, Caltech
“Error correction is the bridge between quantum toys and quantum tools.”
— Dr. Sarah Chen, MIT
Conclusion
+×
Chat
Add a flowchart diagram
Done! I’ve added a flowchart showing the quantum error correction pipeline.
Ask anything about this page...

Above the panel: save, send to Notion, download as Markdown, copy, print, table of contents, regenerate, theme. Beside every section: expand, collapse, strike. Below: chat, per-section web search, revert. Every control is one click.

Built for heavy readers
A reader’s editor for the whole web.
01

The genre decides the summary’s shape.

xTil names what you’re reading — news, tutorial, research paper, film, pull request, Reddit thread, podcast, lecture, recipe, court ruling, and a dozen more — around twenty genres, each with its own template. A news piece gets a timeline and a fact-check; a tutorial gets steps; a paper gets abstract and claims; a film gets a spoiler-protected plot; a pull request gets merge-readiness and a class diagram.

Pick a depth — brief, standard, or deep. The mode doesn’t just shorten the prose; it changes which sections appear. Brief on a paper keeps the abstract and the verdict; deep adds methods, claims, limitations, and a fact-check.

GITHUB PR Claude 3.5
Add streaming response support for chat API
acme/api · PR #847 · opened by @mchen · 12 files changed
✓ 2,180 words +342 / −89 lines
TL;DR
+×
Adds Server-Sent Events streaming to the chat completions endpoint. Refactors the response pipeline to support both buffered and streamed output, with a new StreamManager class handling back-pressure and client disconnects.
Key Changes
+×
1StreamManager class — New src/stream.ts handles chunked transfer encoding, back-pressure, and graceful disconnect.
2API contract — Accepts stream: true parameter; returns SSE with data: frames matching OpenAI format.
3Tests — 14 new test cases covering timeout, reconnect, and partial-chunk edge cases.
Code Quality
+×
Error handling — Proper cleanup on client disconnect via AbortController.
Type safety — Full TypeScript types for stream events and options.
Memory — No explicit buffer size limit in StreamManager; could grow unbounded under slow consumers.
Review Comments (8)
Conclusion
02

Never miss the key point in a 30-minute video

xTil fetches the full video transcript and creates a summary with clickable timestamp links — jump to the exact moment a point was made. Video metadata (channel, duration, views, date) is displayed alongside the thumbnail.

Works on any video with a transcript. Long lectures, podcasts, tutorials — distilled into sections you can skim in seconds.

YOUTUBE GPT-4o
AI IS TURNING INTO SOMETHING TOTALLY NEW 11:42
AI Is Turning Into Something Totally New
Fireship · Jan 8, 2025 · 11:42 · 2.1M views
✓ 4,812 words 1.2K comments
TL;DR
+×
AI is shifting from single-prompt chatbots to autonomous multi-step agents that plan, execute, and self-correct. The new paradigm combines chain-of-thought reasoning with tool use and memory, turning LLMs from parlor tricks into general-purpose problem solvers.
Key Takeaways
+×
1Agentic AI — The industry is moving from chatbots to agents that can browse, code, and execute multi-step workflows autonomously.
2Reasoning models — Chain-of-thought and tree-of-thought approaches let models self-verify before answering.
3Tool use is key — Models that call APIs, run code, and search the web outperform those that rely on training data alone.
Summary
+×
The AI paradigm is undergoing its most significant shift since the introduction of transformers. Rather than larger models trained on more data, the frontier has moved to systems that think step-by-step, use external tools, and maintain persistent memory across sessions.
Fact Check
Notable Quotes
Conclusion
03

The summary is a draft, not a verdict.

Expand or collapse any section with one click. Strike a section you don’t want and it stays gone. Ask for a new one — Timeline, Risks, Glossary, Key Statistics — and xTil writes it. Run a web search inside any section to verify a claim or pull in fresh sources.

Chat with the model about the page in plain language to refine anything else — translate the whole summary, rephrase a paragraph, add a chart. Every change has a revert arrow; no edit is destructive.

REDDIT GPT-4o
Is it worth switching from React to Svelte in 2025?
r/webdev · u/frontenddev42 · 347 comments · 1.2K upvotes
✓ 5,120 words 347 comments parsed
TL;DR
+×
The community is split but leans toward staying with React for large teams and existing codebases. Svelte wins on DX and bundle size, but React’s ecosystem, hiring pool, and Server Components momentum keep it dominant.
Key Arguments
Notable Quotes (6)
Pros & ConsNEW
+×
Svelte DX — Less boilerplate, faster builds, smaller bundles (up to 40% reduction).
Learning curve — Closer to vanilla HTML/JS; easier for junior devs to pick up.
×Ecosystem — React has 10x more packages and battle-tested solutions for every use case.
×Hiring — Finding experienced Svelte developers remains significantly harder.
Conclusion
Chat
What’s the community consensus?
The thread leans toward React for production apps, but Svelte for side projects and smaller teams.
Add a pros & cons section
Added a new Pros & Cons section comparing Svelte and React based on the top-voted arguments.
Ask anything about this page...
04

See how ideas connect at a glance

xTil generates Mermaid diagrams when they genuinely help understanding — not just as decoration. Every chart shape Mermaid supports: flowcharts, sequence diagrams, timelines, ER diagrams, pie charts, mind maps, Gantt charts, Sankey flows, and more.

If a diagram comes back with a syntax error, xTil rewrites it until it renders — up to five attempts, without you lifting a finger.

ARTICLE
✓ 4,100 words 6 images — will analyze
TL;DR
+×
A practical guide to trunk-based CI/CD pipelines that ship every commit to production. Covers quality gates, automated rollbacks via feature flags, and how DORA metrics track deployment health.
Key Takeaways
+×
1Trunk-based flow — Every push to main triggers lint, test, build, and deploy in a single linear pipeline.
2Quality gates — Automated tests must pass before the build image is promoted; failures block the pipeline.
3Zero-downtime deploys — Canary releases with automatic rollback if error rates exceed 0.1% threshold.
4Feature flags — Decouple deployment from release; ship dark features and toggle them independently.
Summary
+×
Modern CI/CD pipelines replace manual gates with automated quality checks. The trunk-based model eliminates long-lived branches and ensures every commit is production-ready.
Push to main Lint & Test Build Image Tests OK? Yes Deploy Prod No Notify & Block
Fact Check
+×
DORA metrics standard — Verified. Used by Google’s DevOps Research team.
Trunk-based reduces lead time — Verified. Accelerate book data confirms.
0.1% error threshold — Contested. Industry standard varies from 0.01% to 1%.
Related Topics
GitOps Canary Deployments Feature Flags DORA Metrics
05

Review PRs and issues in half the time

Six specialized modes: PRs get merge-readiness status with auto-generated class diagrams, issues get triage analysis, code files get potential-issue scanning with line-linked references, repos get tech stack breakdowns, commits get change summaries, and releases get migration guides.

Code review issues are linked to specific lines. Diagrams visualize the architecture so you understand the PR before reading a single diff.

GITHUB PR
✓ 847 lines 12 comments
TL;DR
+×
Migrates the legacy cookie-based login to a full OAuth2 flow with Google and GitHub providers. Adds token refresh, secure storage via encrypted cookies, and a new /auth/oauth callback endpoint.
Open — Ready to merge
Key Takeaways
+×
1New OAuth2 flow — Replaces /api/login with /auth/oauth callback supporting Google and GitHub.
2Token management — Adds TokenStore class with encrypted refresh tokens and automatic expiry handling.
3Backwards compatible — Legacy session cookies are gracefully migrated on first OAuth login attempt.
Summary
+×
This PR restructures the entire authentication layer around an OAuth2 provider pattern, replacing direct password validation with delegated identity providers.
AuthService TokenStore «interface» OAuthProvider GoogleAuth GitHubAuth
Fact Check
+×
Token expiry not validatedauth.ts:47 stores tokens but never checks expiry before use.
Missing CSRF protectionoauth.ts:23 callback doesn’t validate state parameter.
Encrypted cookie storage — Uses AES-256-GCM with rotating keys. Good practice.
Conclusion
+×
Well-structured OAuth2 migration. Fix the CSRF state validation and token expiry check before merging. Otherwise ready for production.
Workflow
Two stages, one extension
1

Open any page

Article, video, paper, pull request, film — whatever you’re reading.

2

Extract the content

Each platform gives up its content differently — a YouTube transcript, a Reddit thread, a PDF’s figures. xTil reads what’s actually there. This stage runs on its own model — pair it with a fast or local one if you like.

3

Distill the meaning

Now xTil names the genre and writes the summary its shape deserves. Use whichever model you want for this stage — frontier for the distillation, local for the read, or a single model for both. Refine, then keep what’s worth keeping.

How it reads
Every platform, read on its own terms.

YouTube

Automatically fetches the full video transcript and creates a summary with clickable timestamp links — jump to the exact moment a point was made. Extracts title, channel, duration, view count, and description.

Netflix

Extracts closed captions directly from the player, with show metadata, thumbnail, maturity rating, and season/episode info shown before you even summarize. Spoiler-protected plot summaries, cast info, and review scores fetched via web search.

GitHub

Six specialized modes: PRs get merge-readiness status and review synthesis, issues get triage analysis, code files get potential-issue scanning with line-linked references, repos get tech stack breakdowns, commits get change summaries, and releases get migration guides.

Reddit

Fetches the complete thread including nested comment chains with upvote scores, flairs, and engagement metrics. Human comments are weighted higher than bots, and recent comments rank above older ones in the analysis.

Twitter / X

Detects threads (consecutive same-author replies) and reconstructs them in order. Extracts engagement metrics — replies, reposts, likes, views — and includes notable replies in the analysis.

Google Docs

Reads the document content directly, maintaining structure and formatting. Works even when the document is behind a login — xTil fetches it from within your authenticated browser session.

Facebook

Detects modal overlays from the feed and extracts just the post — not the entire page. Handles “See more” expansion, multi-image galleries, and pulls reaction/comment/share counts for context.

LinkedIn

Summarize posts from feed or direct URLs. On feed pages, smart detection picks the post with the most screen coverage. Expands truncated text, extracts author headline, engagement metrics, and visible comments.

PDF

Extracts text from academic papers, reports, and any PDF opened in Chrome. Renders vector figures from PDF pages with smart white-space cropping. Works with any PDF — just open it in a tab and summarize.

Your AI, your bill
No subscription. xTil uses the AI you already pay for.

OpenAI

GPT-4o, GPT-4o-mini, o1, o3 · 128K context · Vision

Self-hosted

Ollama, LM Studio, vLLM · any OpenAI-compatible endpoint

Anthropic

Claude Sonnet, Opus, Haiku · 200K context · Vision

Google

Gemini 2.5 Pro, Flash · 1M context · Vision

xAI

Grok 2, Grok 3 · 128K context · Vision

DeepSeek

DeepSeek V3, R1 · 64K context

xTil automatically discovers available models from your provider and probes each model's actual vision capability — so image analysis just works without manual configuration.

Already use ChatGPT or Claude? You likely have an API key. Most summaries cost less than $0.01.

Your key. Your data. Your machine.

xTil has no backend, no proxy, and no middleman. Page content goes directly from your browser to the LLM provider you choose, using your own API key. Settings and summaries stay in your browser. The code is open source — you can verify every line. No accounts, no analytics, no tracking, no servers.

01
Read the source Every line, on GitHub.
02
Read the permissions activeTab, storage, scripting, tabs, sidePanel — plus access to whatever page you ask it to read.
03
Read the changelog Every release, plainly described.
Save what you keep
A summary worth keeping is a summary worth searching.

Notion as a searchable database

Send any improved summary to a Notion database — tagged by genre, model, and source URL. Search later with full-text queries. Share the database with a teammate, or invite them to a single page. The export carries diagrams, fact-checks, and section structure intact.

Markdown for Obsidian and any vault

One click, a clean .md file with front-matter included. Drop it into Obsidian, Logseq, your dotfiles, or paste it into anything that reads CommonMark. No proprietary lock-in.

How it compares
Why xTil?
Feature xTil Generic extensions Generic summarizers Paid tools
Private — your key, no server
Multiple LLM providers
Platform-aware extractionPartial
Genre-aware summary templates
Diagrams & visual output
Chat refinementSome
Free & open sourceFreemiumVaries
Notion database & Markdown export

Read the web the way you always meant to.

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