Duplicate keywords in image ALT text丨New 2025 image SEO rules and penalty cases

2025 will see major platforms like Google introduce stricter algorithm updates targeting this issue.

Repetitive, low-quality ALT text not only fails to convey meaningful information, but may also lead to lower site scores or even traffic penalties.

This article dives into real-world scenarios and highlights common mistakes (like identical ALT tags across product images on e-commerce sites)

to help you avoid “ALT text cannibalization” that could harm your website health and unlock the true search value of your images.

​​What Is Image ALT Text and Why Does It Matter for SEO?

You’ve probably seen the “ALT text” field in your site’s backend but rarely filled it out properly—after all, the image is already there and visible to users, so why bother?

In fact, this seemingly minor ALT attribute is actually the only way search engines can “understand” what your image shows.

Put simply, ALT text is like an image’s ID card: when an image fails to load, it tells users what should be there;

For search engines, it links the image to the page topic, and plays a key role in rankings.

ALT Text Basics: More Than Just a Backup

The core functions of alternative text

1. When an image doesn’t load due to network issues, the ALT text will be displayed in its place, telling users what was supposed to appear (e.g., for a promotional image of a camping tent, the ALT should be something like “2025 windproof camping tent gear,” not just “image1”).
2. For visually impaired users, screen readers rely on ALT text to describe images. If the ALT is missing or vague (like “product image”), you’re basically denying them access to vital content.

The hidden SEO bridge

Search engines can’t visually interpret images (colors, shapes, text in images), so they rely on ALT text to understand the image’s relevance.

Example comparison:

• Poor-quality ALT: Using “hiking shoe image” for all product images of shoes;
• High-quality ALT: “2025 waterproof hiking boots – anti-slip and durable, unisex” (includes context, function, and target users).

How Search Engines Evaluate ALT Text

How algorithms extract meaning

Search engines like Google scan ALT text and cross-check keywords with page titles and content to determine how focused your page really is.

For example, in an article about “camping gear recommendations,” if every image has the ALT “camping gear,” the algorithm may flag the content as repetitive and lower your score.

The direct impact of the 2025 policy update

Stricter quality assessment: In the past, ALT text only needed to contain the right keyword. But under the new rules, it must also offer “information value” and “uniqueness.” For example:

• Old standard: ALT=“hiking boots”;
• New standard: ALT=“lightweight hiking boots – desert yellow, great for multi-terrain treks”.

Relevance penalties: Repeating the same ALT text across multiple images can be marked as “inefficient content,” dragging down your entire site’s SEO performance and killing off image search traffic.

Balancing User Intent with SEO Optimization

Clear, user-focused descriptions

Add context and usage scenarios: Don’t just name the object—add function or usage. For example:

• Basic version: ALT=“coffee machine”;
• Optimized: ALT=“home espresso coffee machine – built-in grinder, one-touch brew”.

Include keywords naturally: Spread out core keywords across different images. For example, in a page about “outdoor camping gear”:

• Tent image ALT = “windproof camping tent – 3-4 person family size”;
• Sleeping bag image ALT = “-10°C warm sleeping bag for camping”.

Avoid common pitfalls

Don’t sacrifice readability for SEO:

Wrong: ALT=“2025 hiking boots hiking boots waterproof hiking boots cheap”;

Correct: ALT=“2025 waterproof hiking boots – slip-resistant soles, perfect for trekking”.

Don’t leave ALT text blank or lazy: Even for decorative icons, give a basic description (e.g., ALT=“back to homepage button”).

Tools to help you audit ALT text

1. Google Search Console: Use the “enhanced image report” to find unindexed images and ALT issues;
2. Screaming Frog: Bulk crawl images across your site and export ALT text lists for review;
3. Ahrefs: Check competitors’ best-performing ALT texts and study their keyword strategies.

Common Problems and Risks of Repetitive Keyword Usage

To quickly boost keyword density, many site managers reuse the exact same keywords across multiple images on a page (e.g., labeling every product image “2025 new sneakers”), or just copy-paste ALT text in bulk.

For users, repetitive descriptions add little informational value;

For search engines, keyword stuffing may be flagged as “content manipulation.”

Google has publicly stated it will step up detection of “inefficient, repetitive content,” especially when it comes to ALT text misuse.

For example, a home décor website labeled 50 different sofa images with the same ALT text “Nordic-style sofa.” The result? Their image search traffic dropped 35% after the algorithm flagged it as “redundant content.”

What kind of repetition triggers penalties?

Using the same ALT text across the entire site

• Case study: An e-commerce site used “2025 new women’s fashion” for every product image ALT. As a result, search engines treated the content as repetitive, showing only the first image in search results and filtering out the rest.
• Consequence: Significant loss of long-tail traffic (e.g., keywords like “2025 spring women’s fashion” or “breathable fabric for women’s wear” become unreachable).

Excessive Keyword Repetition on the Same Page

• Example: In a blog post about “Best Hiking Gear,” all 10 image ALT tags say “Best Hiking Gear,” without distinguishing between specific items (like tents, backpacks, or trekking poles).
• Algorithm Reaction: Google’s BERT model may flag the content as lacking new information, reducing how well the page matches niche search intents.

Copy-Pasting ALT Descriptions Across Pages

Real Case: A travel blog reused the same ALT text “XX City Travel Photo Spot” for images across guides for different cities. As a result, Google Image Search downgraded them, and they lost 40% of their image traffic.

How Do Search Engines Detect “Keyword Stuffing”?

Threshold Criteria & Algorithm Logic

• Repetition Density: If over 30% of image ALT tags on a single page contain the exact same main keyword, it could trigger a penalty (according to Google’s 2025 update docs).
• Semantic Analysis: The algorithm analyzes entities (like product names, features) and scenarios (like “outdoor,” “indoor”) in ALT text. If too many images are semantically identical, it’s marked as low-quality content.

Cross-Page Content Repetition Penalty

Example: A furniture site used “Nordic Style Sofa” as the ALT text for every sofa image across multiple pages. Google’s Sitewide Analysis flagged this as “template-style content,” causing a 50% drop in their indexed images.

New Detection Techniques in 2025

1. TF-IDF Weighting Adjustment: Keywords used too often get lower weight. ALT text with more specific terms (like “waterproof hiking shoes”) now scores better than vague ones (like “hiking shoes”).
2. User Behavior Feedback: If users quickly bounce after clicking an image (because the ALT didn’t match the actual content), the algorithm connects ALT quality to page trustworthiness.

Real Risks & Consequences

Drop in Search Rankings

• Case: A food blog used “home cooking guide” as the ALT for every recipe step image. Its ranking for “braised pork step-by-step” dropped from page 1 to page 5.
• Why: Repeated content weakens the page’s topic relevance, making it harder for search engines to prioritize.

Steep Drop in Image Search Traffic

• Data: An outdoor gear site saw image search traffic drop 35% in 30 days due to repeated ALT text. Recovery took 3 months to rebuild trust with unique content.

Poor User Experience & Lower Conversion Rates

• Scenario: A user expects to see a specific product feature from the ALT text (like “Waterproof Test for Hiking Shoes”), but the image doesn’t match. They exit immediately.
• Outcome: Bounce rate rose 15%, and conversions dropped 8% (based on an A/B test from an independent site).

3 Urgent Fix Steps

1. Spot the Problem: Use Tools & Prioritize

Recommended Tools:

1. Screaming Frog: Export a list of all ALT text on your site, and filter for pages with over 30% repetition.
2. SEMrush: Use the “Site Audit” feature to flag repeated ALT issues and sort them by severity.

Fixing Order: Start with high-traffic pages (like product pages or blog category hubs).

2. Batch Optimize: Diversify ALT Text Strategy

Rule: On the same page, every ALT should include a “main keyword + unique feature.” For example:

3. Monitor & Maintain: Prevent Recurrence

Automation Tools:

1. Google Search Console: Set up alerts for “ALT text repetition” issues.
2. Ahrefs: Regularly track competitor ALT strategies and compare repetition levels.

Manual Review Rule: Content teams must provide “scene + feature + keyword” combo ALT text when uploading images.

2025 Image SEO Rule Changes: What’s New

“Why are my sharp, beautiful images getting less and less traffic?”

In 2025, many site owners discovered that their tried-and-true image SEO tactics suddenly stopped working.

Google officially announced a crackdown on two behaviors: 1) stuffing ALT text with repeated keywords, and 2) weak connection between images and the page topic.

For instance, a photography site used “scenic photo” for all its ALT tags. Google flagged it for “low info density,” cutting image search impressions by 40%.

Updated Quality Evaluation Standards

Why Old Rules Don’t Work Anymore

• Old Logic: Search engines used to rely on keyword density in ALT text to assess relevance (e.g., ALT=“hiking shoes” matched the “hiking shoes” search term).
• What’s Changed: The 2025 update introduces a “contextual information score,” meaning ALT text must include specific features, usage scenarios, or unique traits. Otherwise, it’s treated as low-quality content.

Case Comparison:

New Evaluation Dimensions

1. Information Density: ALT text must cover at least 2 of the following: “main subject + attributes + context”. (e.g., “kids’ thermos” is insufficient, while “kids’ thermos – 450ml anti-drop design, suitable for outdoor trips” meets the requirement.)
2. Cross-Content Consistency: Images must strongly relate to the page topic. For example, if an article is about “camping gear checklist” but includes many irrelevant images with ALT=”new smartphone”, it will lose points.

From Single Image to Full Site Score

Ripple Effects of Repetitive Content

Old Mechanism: ALT issues only affected the visibility of the individual image in search results.

New Mechanism: When repetitive/low-quality ALT text crosses a threshold on a page or site-wide, the following penalties may apply:

1. Page-Level: Lowers the search ranking of the entire page;
2. Site-Level: Reduces the number of images indexed across the entire site (e.g., from 1000 indexed images to only 300).

Real Case: A beauty blog saw a 28% drop in overall traffic within one month because 30% of its product images reused the ALT “lipstick swatch”.

Algorithm Thresholds and Priorities

• Repetition Density Threshold: If over 40% of images on a page use the same ALT keyword, or over 20% site-wide follow the same template (like “XX product image”), penalties may be triggered.
• Priority Rules: High-traffic pages (such as the homepage or top product pages) will be prioritized for algorithmic scanning and penalties.

Google Search Console’s Alert Capabilities

New ALT Health Check Feature

Where to Find It: A new “Image Enhancement Report” section is available in the Search Console sidebar, flagging pages with excessive ALT repetition.

Data Dimensions:

1. ALT repetition ratio (by page/site-wide);
2. List of low-information ALT texts (e.g., generic terms only);
3. Relevance score between image and page topic (scale of 0-100, warnings triggered below 60).

How-To Guide: 3-Step Risk Check

• Step 1: In Search Console, go to “Image Enhancement Report” and export the list of “high repetition rate pages”;
• Step 2: Click on specific pages to review sample repetitive ALT texts and the related images;
• Step 3: Use the “Suggested Optimization” tool to get ALT template recommendations from the algorithm (e.g., “{Product Name} + {Key Feature} + {Use Case}”).

Key Actions to Adapt to the New Rules Cost-Effectively

Optimizing Existing Content: 3 Priority Levels

1. Urgent Optimization: Top 10 traffic pages + pages with ALT repetition >40%;
2. Moderate Optimization: Product detail pages / blog category pages with low-information ALT texts;
3. Can Temporarily Ignore: Decorative-only images (e.g., icons, dividers), but still ensure ALT is not empty (e.g., ALT=”decorative pattern”).

New Content Rules: Mandatory for Content Teams

ALT Writing Template: Subject + Attribute + Scene (e.g., “Portable Bluetooth speaker – IPX7 waterproof, great for outdoor camping”);

Review Tools:

• Chrome extension “Alt Text Tester” for real-time ALT info checks;
• Notion database template: Forces ALT field completion when uploading images.

Cost Control Tips: Batch Processing Tools

Option 1: Use WordPress plugin “SEO Image Optimizer” to batch replace repetitive ALT texts and auto-generate diverse descriptions based on rules;

Option 2: For large websites, use a Python script to scrape image URLs and ALTs, then batch rewrite using the ChatGPT API (costs around $0.02/image).

Real Penalty Case Studies and Solutions

Google has shifted from a “lenient crawl” approach to an “active filtering and elimination” strategy for ALT review.

Just avoiding mistakes isn’t enough — you must proactively prove your content’s value.

Example: An outdoor gear site reused “hiking boots” as the ALT text on 300 product images. The algorithm flagged it as a “content farm,” and image search traffic dropped by 50% in a week.

In-Depth Case Analysis: 3 Real Scenarios

Case 1: E-commerce Site — Massive ALT Repetition Halves Traffic

Background: A sports shoe e-commerce site used “2025 new sports shoes” as the ALT for over 800 product images across the site, without differentiating by model, features, or intended use.
Penalty Impact：

1. Image search traffic dropped 52% within 30 days;
2. Core keywords like “breathable running shoes” and “waterproof hiking shoes” dropped out of the top 50 rankings;
3. Google Search Console flagged “ALT content duplication rate too high.”

Algorithm Logic：

• Search engines believe the page lacks informational depth and fails to meet specific user needs (e.g., “running shoes” and “hiking shoes” target different intents);
• Duplicate content triggered a “template content” penalty, lowering image indexing priority across the site.

Case 2: Travel Blog — Generic Descriptions Excluded from Image Search

Background：A Europe travel guide blog used generic ALT texts like “Paris travel” or “Rome attractions” for all landmark images.

Penalty Impact：

1. Zero exposure in landmark image searches (no ranking for long-tail queries like “Eiffel Tower night view” or “Colosseum interior”);
2. Page dwell time dropped 40% (users quickly left the page after clicking images due to irrelevant content).

Algorithm Logic：

• In 2025, Google Image Search emphasizes “precise scene matching,” and generic ALT tags don’t connect with specific landmark features;
• High bounce rates negatively affect overall page quality scores.

Case 3: Corporate Website — Empty ALT Tags on Decorative Images Cause a Domino Effect

Background：A B2B industrial equipment site left all decorative icons and separator images with empty ALT attributes or labeled them simply as “image.”

Penalty Impact：

1. Mobile page experience score dropped to 65/100 (a key Google algorithm metric);
2. Organic search traffic declined by 18%, as the algorithm considered the pages “incomplete.”

Algorithm Logic：

• Missing ALT on decorative images affects accessibility scores, indirectly lowering overall page quality;
• Empty ALT tags are seen as a fundamental optimization failure.

The Algorithm Logic Behind Penalties

Content Quality Scoring System

• ALT Information Density Score: Based on number of entity keywords and richness of scene description in ALT text (0-1 scale). Scores below 0.3 trigger warnings.
• Page Topic Deviation: If ALT text relevance to the page’s core keyword is under 60%, it’s labeled as “distracting content.”

Impact of User Behavior Data

• Bounce Rate Penalty: If a user enters via image search and leaves within 5 seconds, that image’s search weight is reduced;
• Click-Through Rate Decay: Repetitive ALT text leads to similar search results, reducing click diversity and hurting rankings.

New Associated Penalty Rules in 2025

• Site-Wide Penalty Mechanism: If a single page has 3+ ALT issues, image indexing speed is slowed down by 50% site-wide;
• Cross-Device Score Sync: ALT issues on mobile pages also affect desktop search performance.

Scene-Based Fixes

E-commerce Sites: Differentiated ALT + Attribute Tag Integration

Steps：

1. Use Screaming Frog to export all product image ALT texts and filter SKUs with >70% duplication;
2. Batch rewrite in the format: “Product Name + Key Feature + Usage Scenario” (e.g., change “hiking shoes” to “Men’s Non-Slip Hiking Shoes – Waterproof & Durable for Mountain Trails”);
3. Add “product attribute tags” (e.g., waterproof rating, weight) to product pages to semantically support the ALT text.

Tools：

• WooCommerce plugin “ALT Auto Generator” (auto-generates ALT text based on product parameters);
• Sync updated image ALT text via Google Merchant Center to improve ad relevance.

Niche Blogs: Long-Tail Keywords + Scene-Based Layering

Steps：

1. Use Ahrefs to find target long-tail keywords (e.g., “best angles to photograph Eiffel Tower at night”);
2. Layer ALT texts for the same landmark:
3. Main image ALT = “Eiffel Tower at night – reflection from Seine River”;
4. Detail image ALT = “Eiffel Tower lighting detail – 2025 golden illumination effect”;
5. Add captions below images that align with the ALT text.

Tools：

• Surfer SEO content editor: detects real-time keyword alignment between ALT text and body content;
• Canva: embed invisible text layers in image design to aid search engine recognition (use with caution).

Corporate Sites: Minimal Compliance Fixes

Steps：

Standardize ALT for decorative images (e.g., separator ALT = “decorative line – brand color”);

Clarify ALT for functional icons (e.g., PDF icon ALT = “Download product brochure PDF”);

Use Lighthouse tool to check accessibility scores and prioritize fixes for pages scoring below 90.

Tools：

AccessiBe: automated ALT generation and compliance detection;

WordPress plugin “Automatic Alt Text”: AI-based ALT filler using surrounding text context.

Long-Term Prevention Strategy: Build an ALT Review SOP

Content Team Training Standards

• 4 ALT Writing Elements: Subject + Function + Scene + Unique Keyword (e.g., “conference table” → “Walnut conference table – seats 10 with built-in power ports”);
• Red Flag List: No empty ALT, no meaningless names like “image123,” no copy-pasting site-wide.

Automated Monitoring System
Routine Checks:

1. Scan the entire site weekly using Screaming Frog to check ALT text and generate a duplication report.
2. Download “ALT health” data monthly from Google Search Console to track improvement progress.

Alert System:

Set up automated alerts via Zapier: If ALT duplication rate on any page exceeds 30%, trigger an email notification;

Use Datadog to monitor fluctuations in image search traffic, and automatically flag related pages when there’s an unusual drop.

Cross-Department Collaboration Rules

Design Team: When delivering images, also suggest ALT text (e.g., “Main product image should highlight key selling point”);

Development Team: Block CMS from allowing image uploads without filling in ALT text;

Marketing Team: Include ALT text in ad material review process to ensure consistency with the landing page.

Practical Strategies for Optimizing ALT Text

“Isn’t optimizing ALT text just about stuffing in more keywords?” — This misconception caused many sites to suffer under the new 2025 SEO rules.

In reality, great ALT text should be written like a ‘mini ad copy’: It should help search engines understand the image while quickly giving users valuable info.

For example, a home decor site changed its ALT text from “sofa” to “Scandinavian fabric sofa – space-saving for small living rooms” and saw a 65% boost in image search traffic, with a 20% increase in user dwell time.

4 Steps to Writing High-Converting ALT Text

Step 1: Break Down User Search Intent

The Key Idea: ALT text should directly address image-related search queries. For example, someone searching “waterproof hiking boots” probably wants to know about performance, use scenarios, or real-world results.

How to Do It:

1. Use tools like Ahrefs or AnswerThePublic. Enter a main keyword (like “hiking boots”) and pull long-tail questions (e.g., “how to test hiking boots for waterproofing,” “what terrains are hiking boots good for”);
2. Incorporate those question keywords into the ALT text (e.g., ALT=“Waterproof hiking boots test photo – splash test demo”).

Step 2: Use the ‘Scene + Pain Point + Data’ Formula

Before vs After Examples:

Formula Breakdown:

• Scene: Show real-life usage (e.g., “gym,” “working from home”);
• Pain Point: Solve a user concern (e.g., “cable clutter,” “short insulation time”);
• Data: Add measurable info (e.g., “500ml,” “24 hours”).

Step 3: Use Unique Keyword Combos

Pro Tip: ALT text for multiple images on the same page should each highlight different aspects:

• Product Image 1: ALT=“Hiking boots waterproof test – splash demo in action”;
• Product Image 2: ALT=“Hiking boots weight check – only 280g per shoe”;
• Context Shot 3: ALT=“Hiking boots on rocky trail – anti-slip grip showcase”.

Step 4: A/B Test to Measure Impact

Recommended Tools:

Google Optimize: Set two ALT versions for the same image and compare click-through rates;

Hotjar: Use heatmaps to see how long users engage with content related to different ALT texts.

Optimization Cycle: Iterate every 2 weeks and prioritize versions that improve CTR by 10% or more.

Free Tools vs. Paid Solutions

Free Tools

ALT Text Generators:

• ChatGPT-4o (Free Version): Just enter a prompt like “Generate SEO-friendly ALT text with scene and pain point. Keyword: hiking boots” and get instant copy suggestions;
• Bulk Alt Text Editor (Chrome Extension): Lets you bulk-edit ALT text on a page, supports regex-based replacements.

Quality Check Tools:

• WAVE Evaluation Tool: Checks if ALT text meets accessibility standards, flags missing or duplicate issues;
• Lighthouse: Run it inside Chrome DevTools to see how ALT text affects page performance scores.

Paid Tools

Bulk Generation:

• SEO Image Optimizer (WordPress Plugin, $49/year): Automatically analyzes images and generates ALT text with keywords;
• DeepAltText (API Service, $0.01/image): Uses AI to recognize the main subject, color, and scene, then generates natural language ALT text (e.g., detects a coffee machine → ALT = “Silver espresso machine with steam wand in action”).

Monitoring & Analysis:

• Botify: Scans your whole site to identify duplicate ALT text and flags high-risk pages (starts at $399/month);
• Moz Pro: Tracks ranking changes related to ALT keywords and creates competitor comparison reports (starts at $99/month).

Creative Ways to Avoid Repetition

Dynamic Parameter Insertion

Best For: E-commerce product images, blog visuals generated in bulk.

How It Works:

Original ALT template: “{Product Name}-{Color}{Material}{Use Case}”;

Dynamically generated examples:

• “Hiking boots – black GTX fabric for trekking”;
• “Hiking boots – navy mesh for urban commuting”.

Tools to Use: WordPress plugin “Dynamic Alt Text” or Shopify app “SEO Image Optimizer”.

Storytelling from the User’s Perspective

Example:

Basic ALT: “Coffee machine instruction image”;

Storytelling ALT: “First-time using a coffee machine: a step-by-step real photo guide from grinding to brewing”.

Effect: Boosts user engagement, reduces bounce rate, and captures long-tail keywords like “how to use a coffee machine”.

Cross-Media Content Strategy

Approach: Sync your ALT text with video subtitles and product spec sheets to build a strong content matrix.

Example:

Image ALT: “Waterproof test for hiking boots – live experiment”;

Video Subtitle: “Click to watch the full waterproof test video”;

Spec Sheet Label: “GORE-TEX certified waterproofing, tested up to 20,000mm water pressure”.

Automation Strategies for Long-Term Maintenance

Rule 1: Mandatory Checks in CMS

How to Set It Up:

• In platforms like WordPress or Shopify, enforce a minimum ALT text length (e.g., 15+ characters) or block image uploads;
• Use custom field templates (e.g., require “Scene” and “Function” fields before publishing).

Rule 2: Automated Monitoring Alerts

Setup Ideas:

• Zapier Workflow: When Google Search Console spots duplicate ALT text, auto-notify a Slack channel;
• Google Alerts + Custom Script: Watch for unusual changes in image search traffic and trigger email alerts.

Rule 3: Quarterly ALT Content Review

Steps:

1. Every quarter, use Screaming Frog to crawl all image ALT text and export a CSV report;
2. Use Excel formulas (like =COUNTIF) to highlight duplicates;
3. Prioritize fixing the top 10% of pages with the most duplicates.

Both users and algorithms want denser, more valuable content.

And the ALT text of an image can be the proof that you know your audience and your product better than your competitors.