I built Site Spy after missing a visa appointment slot because a government page changed and I didn’t notice for two weeks.It watches webpages for changes and shows the result like a diff. The part I think HN might find interesting is that it can monitor a specific element on a page, not just the whole page, and it can expose changes as RSS feeds.So instead of tracking an entire noisy page, you can watch just a price, a stock status, a headline, or a specific content block. When it changes, you can inspect the diff, browse the snapshot history, or follow the updates in an RSS reader.It’s a Chrome/Firefox extension plus a web dashboard.Main features:- Element picker for tracking a specific part of a page- Diff view plus full snapshot timeline- RSS feeds per watch, per tag, or across all watches- MCP server for Claude, Cursor, and other AI agents- Browser push, Email, and Telegram notificationsChrome: https://chromewebstore.google.com/detail/site-spy/jeapcpanag...Firefox: https://addons.mozilla.org/en-GB/firefox/addon/site-spy/Docs: https://docs.sitespy.appI’d especially love feedback on two things:- Is RSS actually a useful interface for this, or do most people just want direct alerts?- Does element-level tracking feel meaningfully better than full-page monitoring?
FL score
out of 100
Verdict
high confidence
Competition
10
competitors found, emerging market
Trend
8 community mentions
A web page change monitoring tool with unique element-level tracking, RSS feeds, and AI agent integration, targeting specific, high-pain use cases in a growing market.
The pain
The gap
Build angle
Strengths
Questions about this idea?
FlyBot reads the scoring and gives you a second opinion on “I built a tool that watches webpages and exposes changes as RSS”.
Risks
Next steps
Fly Labs Method
Is the pain real, is there a gap, is it the right time, can one person build it.
A highly specific solution addressing real pain points around noisy web monitoring, with a unique angle (element-level tracking, RSS, AI agent integration) in a growing, competitive market.
Value Equation
Dream outcome and how likely it feels, against the time and effort it costs.
This idea offers a compelling value proposition in a growing market, with strong potential for differentiation through its unique features and AI integration.
One-Person Business
Curiosity pull, identity fit, and a path from free value to paid for a solo creator.
A highly focused solution born from a personal need, offering a clear value proposition with good monetization potential and leverage for future projects.
Viral Frameworks
Hook strength, shareability, and how cheaply it can be tested.
A micro-SaaS with a clear, measurable value proposition for a specific audience, leveraging existing distribution channels and a proven business model.
Builder Lens
Evidence the problem exists, timing, defensibility, and a model that fits on a napkin.
A highly specific, much-needed solution addressing real pain, with a clear MVP and a strong future outlook.
Why this verdict
Five lenses, one composite. How scoring works
The angle
This weekend
Who is already there, emerging market
Monitors website changes (visual, text, HTML) and sends alerts via email, browser, or SMS, offering AI-generated summaries of changes.
Pricing: Free plan (5 pages, daily checks); Paid plans start at $14/month (10 pages, 1,000 checks/month); Business+ plan at $140/month (AI features, Slack/Teams alerts, API access).
Offers both local (browser extension) and cloud-based website change monitoring with advanced visual selector technology and filtering conditions.
Pricing: Free plan (25 local monitors, 5 cloud monitors); Paid plans start at $15/month for cloud monitoring.
An open-source, self-hosted website change detection monitoring and notification service, with a cloud-based subscription option.
Pricing: $8.99/month (up to 5,000 URLs, 5-minute re-check times, 85+ notification types). Open-source version is free for self-hosting.
A cloud-based website monitoring software that tracks content, HTML, and availability changes, sending alerts and archiving history.
Pricing: Free plan (3 URLs, 6 checks/day); Lite ($12/month for 25 pages); Essential ($36/month for 100 pages); Business ($78/month for 200 pages); Enterprise (custom pricing).
A fully managed cloud-based monitoring service with AI-powered change summaries and multiple notification channels.
Pricing: Free plan (6 monitored pages, 1 daily check per page, 180 total checks/month); Paid plans start at $8/month (100 pages).
An AI-powered tool that monitors any website for visual, content, source code, technology, availability, or price changes.
Pricing: Not explicitly found in search results, but described as a comprehensive change monitoring app.
An AI-powered platform designed to monitor website changes in real-time with instant alerts on content modifications.
Pricing: Not explicitly found in search results.
A desktop-based tool that detects changes on web pages through configurable checks, content comparisons, and alerts.
Pricing: €49 one-time purchase.
Monitors web pages for changes and sends notifications via email, Discord, or Telegram, focusing on simplicity and straightforward monitoring.
Pricing: Free plan (3 cloud monitors, hourly checks); Paid plans start at $5.59/month for unlimited monitors.
An AI agent that reads pages, follows links to discover new content, and answers questions about what changed.
Pricing: $14/month for unlimited checks.
What they charge
What people say, 8 mentions
Solo founder, $20k MRR, zero ads, zero employees. Here's exactly what worked
r/SaaS
From “blocked by a top creator” to a working X growth system
r/Entrepreneur
I started my business without a dime 3 years ago and managed to scale it to multi-6 figures/year. Sharing my insights here for anyone who needs to read this.
r/Entrepreneur
took 3 years off after my exit. coming back feels harder than starting from scratch
r/Entrepreneur
I’m 18, had my first big win in business, lost most of it + got betrayed, and now I’m stuck in a rut
r/Entrepreneur
Business owners: I'm 16, from Argentina, and just closed a $2,4K deal with a massive influencer. What advice would you give me?
r/Entrepreneur
Sick of paying $300/mo for 3 analytics tools. Built one that replaces them all
r/SaaS
I built a tool that automatically clips videos… curious what people think
r/SaaS
Recent news
Website Change Monitoring Tool 2026-2033 Trends: Unveiling Growth Opportunities and Competitor Dynamics
vertexaisearch.cloud.google.com, January 22 2026
Best 5 Free Website Change Monitoring Tools 2026 - Visualping
vertexaisearch.cloud.google.com, February 17 2026
Best WebSite-Watcher alternatives of 2026 - FitGap
vertexaisearch.cloud.google.com, March 2026
Top changedetection.io Alternatives in 2026
vertexaisearch.cloud.google.com, 2026
Top 10 Visualping Alternatives & Competitors in 2026 - G2
vertexaisearch.cloud.google.com, 2026
Market signals
The website change monitoring tool market is projected for substantial expansion, expected to reach $30.4 billion by 2025 with a CAGR of 21.1% from 2025. This growth is driven by the increasing reliance on digital platforms, the need for website uptime and performance, and the growing complexity of website architectures. AI integration is a key trend, with many tools now offering AI-powered change summaries and noise filtering.
What frustrates people
Last summer we faced a conundrum at my company, Tiger Data, a Postgres cloud vendor whose main business is in timeseries data. We were trying to grow our business towards emerging AI-centric workloads and wanted to provide a state-of-the-art hybrid search stack in Postgres. We'd already built pgvectorscale in house with the goal of scaling semantic search beyond pgvector's main memory limitations. We just needed a scalable ranked keyword search solution too.The problem: core Postgres doesn't provide this; the leading Postgres BM25 extension, ParadeDB, is guarded behind AGPL; developing our own extension appeared daunting. We'd need a small team of sharp engineers and 6-12 months, I figured. And we'd probably still fall short of the performance of a mature system like Parade/Tantivy.Or would we? I'd be experimenting long enough with AI-boosted development at that point to realize that with the latest tools (Claude Code + Opus) and an experienced hand (I've been working in database systems internals for 25 years now), the old time estimates pretty much go out the window.I told our CTO I thought I could solo the project in one quarter. This raised some eyebrows.It did take a little more time than that (two quarters), and we got some real help from the community (amazing!) after open-sourcing the pre-release. But I'm thrilled/exhausted today to share that pg_textsearch v1.0 is freely available via open source (Postgres license), on Tiger Data cloud, and hopefully soon, a hyperscalar near you:https://github.com/timescale/pg_textsearchIn the blog post accompanying the release, I overview the architecture and present benchmark results using MS-MARCO. To my surprise, we were not only able to meet Parade/Tantivy's query performance, but exceed it substantially, measuring a 4.7x advantage on query throughput at scale:https://www.tigerdata.com/blog/pg-textsearch-bm25-fu
AI
Hi HN!I recently switched from a Fedora/GNOME laptop to a MacBook Air. My old setup served me well as a portable workstation, but I’ve started traveling more while working remotely and needed something with similar performance but better battery life. The main thing I missed was a simple taskbar that shows the windows in the current workspace instead of a Dock that mixes everything together.I built boringBar so I would not have to use the Dock. It shows only the windows in the current Space, lets you switch Spaces by scrolling on the bar, and adds a desktop switcher so you can jump directly to any Space. You can also hide the system Dock, pin apps, preview windows with thumbnails, and launch apps from a searchable menu (I keep Spotlight disabled because for some reason it uses a lot of system resources on my machine).I’ve been dogfooding it for a few months now, and it finally felt polished enough to share.It’s for people who like macOS but want window management to feel a bit more like GNOME, Windows, or a traditional taskbar. It’s also for people like me who wanted an easier transition to macOS, especially now that Windows feels increasingly user-hostile.I’d love feedback on the UX, bugs, and whether this solves the same Dock/Spaces pain for anyone else.P.S. It might also appeal to people who feel nostalgic for the GNOME 2 desktop of yore. I started my Linux journey with it, and boringBar brings back some of that feeling for me.
AI
### Describe the project you are working on Godot C# bindings ### Describe the problem or limitation you are having in your project For the past weeks, I've been discussing with several Unity users intending to move to Godot C# regarding dealing with the C# garbage collector. The most common complaint I hear from users is that, in Unity, allocations can trigger unexpected GC spikes into the game. In Godot, we target to make all of the high performance APIs (those that intended to be called every frame) not allocate any memory, so theoretically the GC should not be a problem. Additionally, Godot starting from 4.0, uses the Microsoft CoreCLR version of .net, which also supposedly has a better garbage collector than Unity. But in all, after several discussions with Unity users, neither is enough reassurance for them, and they would really feel safer if Godot exposed a zero allocation API. ### Describe the feature / enhancement and how it helps to overcome the problem or limitation The idea of this proposal is that Godot exposes zero allocation versions of many functions in the C# API, that users can use if they desire. Technically, this could be done from the binding generator itself, without breaking compatibility, and without doing any modification to Godot itself. ### Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams **WARNING** I am not familiar with C#, so take this as pseudocode. Imagine you have two functions exposed as to C#: ```C# void MyClass.SetArray( Vector2[] array); Vector2[] MyClass.GetArray(); ``` This works and is pretty and intuitive. However, it has two problems: * GC is allocated on return * Memory is copied to Godot native formats every time there is a call. The idea is to add NoAlloc versions, which can be generated directly by the binder automatically when required: ```C# void MyClass.SetArrayNoAlloc( Godot.Collections.PackedVector2Array array); void MyCl
AI