OnChange journal
Website monitoring and accessibility
Clear guides to accessibility testing, audit scoping, website change alerts, and technical SEO. Practical examples and checklists from the OnChange team.
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44 articles
- Accessibility agencies
Continuous Accessibility Monitoring: A Guide for Agencies
Build an ongoing accessibility monitoring service with clear coverage, review schedules, client responsibilities, evidence, and practical reporting.
10 min read - Accessibility agencies
Why Website Change Monitoring Matters for Accessibility
Understand how content, CSS, components, mobile states, and vendor updates affect accessibility, with practical review decisions for agency teams.
10 min read - Accessibility agencies
Accessibility Monitoring Reports: An Agency Client Template
Create useful client accessibility reports with a worked monthly example, reconciled findings, coverage gaps, retest evidence, and clear ownership.
11 min read - Accessibility testing
Screen Reader Accessibility Testing: A Practical Guide
Plan screen reader reviews with defined environments, meaningful navigation, complete tasks, dynamic updates, and findings another reviewer can reproduce.
6 min read - Accessibility testing
Testing Zoom, Reflow, and Text Spacing for Accessibility
Review text enlargement, 320 CSS pixel reflow, and spacing overrides with a state matrix, careful exception decisions, and evidence for repeatable retests.
6 min read - Accessibility testing
WCAG Color Contrast Testing: A Practical Guide
Measure text, controls, and meaningful graphics in their actual states, check information conveyed by color, and record precise contrast findings.
6 min read - Accessibility testing
Image Alt Text Accessibility Testing: A Practical Guide
Review image descriptions by purpose and context, including decorative assets, linked images, icons, screenshots, and useful equivalents for complex graphics.
6 min read - Accessibility testing
Manual vs Automated Accessibility Testing: A Practical Plan
Combine automated checks with manual review using a coverage matrix, complete journeys, and reproducible findings that show what was actually tested.
6 min read - Accessibility testing
Keyboard Accessibility Testing Checklist
Test complete tasks with a keyboard, including focus order, visible focus, overlapping content, composite widgets, dialogs, errors, and a repeatable retest.
6 min read - Accessibility testing
Accessible Form Testing: Labels, Errors, and Recovery
Review form labels, instructions, error descriptions, announcements, and recovery with a state matrix and practical steps for a reproducible manual test.
7 min read - Accessibility testing
Accessible Authentication: A WCAG 2.2 Testing Checklist
Plan WCAG 2.2 sign-in checks for password-manager support, whole-code paste, challenges, alternatives, and recovery, with clear AA and AAA boundaries.
6 min read - Audit scoping
How to Write an Accessibility Audit Scope
Define the pages, journeys, states, and evidence an accessibility audit will cover, with a practical scope template and clear rules for unresolved gaps.
6 min read - Audit scoping
Choosing Representative Pages for an Accessibility Audit
Build an audit sample around distinct layouts, important journeys, and interface states. Use a coverage matrix to explain why each page belongs in the sample.
5 min read - Audit scoping
Why a Website Crawl Misses Pages and How to Check Coverage
Reconcile sitemap URLs, discovered links, redirects, blocked pages, and crawl limits before treating a website inventory as a reliable audit boundary.
5 min read - Audit scoping
Estimating Accessibility Audit Effort Beyond Page Count
Estimate audit effort from unique templates, interactive states, complete journeys, and reporting work, with a transparent example you can adapt.
5 min read - Audit scoping
Building an Accessibility Audit Evidence Handoff
Give clients and developers an audit package they can act on: stable page references, reproducible findings, ownership, retest evidence, and scope notes.
5 min read - Audit scoping
What to Retest for Accessibility After a Website Release
Connect release changes to accessibility evidence, choose a focused retest scope, and record what changed without treating an unchanged screenshot as proof.
5 min read - Change monitoring
Reducing Noisy Website Change Alerts Without Missing Updates
Separate rotating content and unstable captures from meaningful changes using narrow targets, tested ignore rules, and a review process for uncertain alerts.
5 min read - Change monitoring
Choosing CSS Selectors That Survive Website Updates
Target the right price, notice, or content block with stable CSS selectors. Check match counts and learn when a missing element needs investigation.
4 min read - Change monitoring
Monitoring JavaScript Websites When the Page Keeps Changing
Diagnose loading states, delayed fonts, consent screens, and client-rendered content so your monitor compares a consistent and meaningful page state.
5 min read - Change monitoring
Managing Visual Regression Baselines After a Redesign
Decide when to accept a new screenshot baseline, keep approvals traceable, and separate intended design changes from regressions during a website redesign.
5 min read - Change monitoring
HTML, CSS, and Screenshots: What Each Evidence Format Proves
Understand the different questions saved HTML, archived styles, and screenshots can answer, and build a website evidence package with clear limitations.
5 min read - Change monitoring
A Practical Routing Playbook for Website Change Alerts
Give every important website change an owner, response target, and resolution path, with an escalation matrix for content, engineering, and accessibility teams.
5 min read - Technical SEO
Monitoring robots.txt for Accidental Crawl Restrictions
Review robots.txt changes by affected crawler and URL path, preserve the previous rules, and distinguish crawl restrictions from indexing controls.
4 min read - Technical SEO
Monitoring Sitemap Changes Without Treating Every URL as New
Track real sitemap additions and removals, reconcile redirects and canonical URLs, and investigate coverage changes without overreacting to file reordering.
4 min read - Technical SEO
A Release Checklist for Canonical and Noindex Changes
Check canonical URLs, robots directives, response headers, and rendered pages after releases, using expected values for each important page type.
5 min read - Technical SEO
What to Monitor Before and After a Website Migration
Build a migration watchlist covering redirect destinations, content, indexing signals, and critical journeys, with separate checks for launch and follow-up.
5 min read - Change monitoring
JSON API Changes: Array Noise, Missing Fields, and Real Risk
Distinguish response reordering from changed API meaning. Compare stable records, preserve null and missing-field differences, and validate the consumer impact.
5 min read - Change monitoring
Monitoring Product Variants Without Mixing Prices and Stock
Keep product, variant, currency, region, and purchase terms consistent when tracking ecommerce prices and availability across changing product pages.
5 min read - Buyer's Guide
Best Change Detection Software in 2026: A Buyer's Guide
OnChange's comparison of eight change detection tools in 2026, covering features, pricing, and the workflows each one supports.
16 min read - Buyer's Guide
How to Choose a Change Detection Tool: 10 Things That Matter
A practical framework for evaluating change detection tools. Ten questions to ask in a trial and the red flags to walk away from.
12 min read - Comparison
Visualping vs Distill.io vs OnChange: A 2026 Comparison
Three of the most-searched change detection tools, compared head-to-head. Features, pricing, alert quality, and who each one is built for.
11 min read - Guide
The 2026 guide to free website screenshot tools
Free URL-to-PNG tools have moved past bookmarklets. What to look for in 2026: JavaScript SPA rendering, full-page auto-scroll, CSS selector clipping, viewport emulation, and multi-device captures.
11 min read - Guide
Mobile screenshot testing across responsive breakpoints
Catch mobile regressions without a real device farm: pick the right breakpoints, screenshot every one on a schedule, diff each release. Tools, viewport choices, and the QA workflow that scales.
9 min read - Pillar Guide
Website Monitoring: The Complete Guide (2026)
A plain-English guide to uptime, visual diffs, API monitoring, selector targeting, accessibility scans, and alert routing for modern teams.
18 min read - Checklist
The WCAG 2.2 Compliance Checklist (A, AA, AAA)
A practical WCAG 2.2 checklist for teams preparing accessibility audits, VPAT reviews, and regression monitoring workflows.
14 min read - Use Case
E-commerce Monitoring: Track Product Pages, Stock & Prices
Your site might be up but showing the wrong price or stale inventory. Learn why content monitoring is the missing layer in e-commerce.
11 min read - Guide
Website Monitoring Best Practices for 2026
A comprehensive guide to setting up reliable website monitoring. Learn how to choose check intervals, configure alerts, and avoid common pitfalls.
12 min read - Industry
Compliance Monitoring: Track Legal & Regulatory Website Changes
Financial services, healthcare, and legal teams need audit trails when web content changes. Automate regulatory compliance monitoring.
10 min read - Explainer
Website Uptime vs Change Monitoring: What's the Difference?
Uptime monitors check if a page loads. Change monitors check if the content is correct. These are fundamentally different problems.
9 min read - Deep Dive
Visual Diff Detection Explained: How Screenshot Comparison Works
Understand the technology behind pixel-level change detection. From screenshot capture to perceptual hashing.
10 min read - Guide
How to Track Competitor Prices Automatically in 2026
Manual price checks don't scale. Discover how teams use CSS selector targeting and scheduled monitors to track competitor pricing.
9 min read - Guide
API Monitoring 101: Track JSON Endpoints for Changes
REST APIs change without warning. Learn how to monitor JSON responses, track schema drift, and alert on breaking changes.
9 min read - Use Case
SEO Monitoring: Detect Website Changes That Impact Rankings
Title tags, meta descriptions, and canonical URLs can change without your knowledge. Catch modifications before they impact rankings.
8 min read
Put the guidance into practice
Start with five monitors and route changes by email, Slack, Discord, or webhook.