Before you compress, crop, rename or write alternative text for a website image, decide what the image is doing there.
What should a buyer become more able to identify, verify, compare, understand or do because that exact visual occupies that exact space? If nobody can answer, the team is not optimising an asset. It is polishing an assumption.
My rule is that an image must earn its page job before it earns production time. A technically perfect file can still be decorative clutter, borrowed proof or visual theatre.
TL;DR
- Separate the editorial job (what the image means here) from the delivery treatment (how it survives in the browser). Decide the first before the second.
- Run the disappearance test: remove the image and name what the buyer can no longer identify, verify, compare, understand or do.
- A photograph makes claims through placement. Stock is atmosphere, never evidence of your people, premises or work.
- Give every proof-bearing image a job card, and accept that the honest answer is sometimes "no image required".
Image SEO begins before the file exists
Most image-optimisation lists begin too late. They start with format, dimensions, compression, filenames, loading and alt text. Those decisions matter, but they assume the correct image has already been chosen for a useful purpose. That assumption fails constantly in website design.
A redesign needs a hero image, so somebody searches a stock library. A service section has an empty rectangle, so a generic team photograph arrives. A case-study card needs visual weight, so a pristine “after” image appears without a project record. The page looks finished. Nobody can explain what became easier for the customer.
I separate the image’s editorial job from its delivery treatment. The editorial job defines the meaning: what the visual shows, why it matters here, what it does not prove and which detail carries the information. Delivery treatment determines how that meaning survives in the browser: crop, size, format, responsive variants, loading behaviour, markup and text alternatives.
Reverse the order and each specialist optimises a different imagined purpose. The designer preserves balance. The developer preserves performance. The SEO specialist preserves keywords. The accessibility reviewer tries to reconstruct meaning from the finished layout. The file gets better. The decision gets no easier.
Use the disappearance test
Remove the image temporarily and ask what the reader loses. If the page merely feels emptier, the image may be honest decoration. Decoration is not a moral failure. A visual can create rhythm, atmosphere and brand character without carrying information. The problem begins when the business presents atmosphere as evidence.
If removal makes it harder to recognise a component, compare two states, follow a process, understand a spatial relationship, inspect a product detail or use an interface control, the image has an informational or functional job.
If the visual disappears, which specific identification, verification, comparison, explanation or action becomes harder?
“The page feels less premium” is an aesthetic consequence. “The buyer can no longer distinguish the two connector types” is a decision consequence. Both may matter, but they demand different treatment and should not be described as the same value.
The test is deliberately commercial as well as editorial. Growth marketing brings people to pages; conversion rate optimisation attempts to improve the journey; branding shapes recognition and expectation. None benefits when a prominent image creates confidence without helping the buyer understand the offer.
A photograph can make a claim without a caption
Images assert meaning through subject, placement, crop and surrounding copy. A photograph under Our Brighton projects can imply that the work took place in Brighton. A group portrait beneath Meet the team can imply employment. A pristine room beside a renovation service can imply a result. A warehouse image on a contact page can imply a staffed location. The image does not need to contain a false sentence. The page creates the proposition.
That is why licensed stock should be treated honestly. Stock photography can establish a category, create mood or support a visual identity. It does not become evidence of the company’s people, premises, process or completed work merely because the licence permits commercial use. I would rather label an illustration, use stock as obvious atmosphere or leave white space than make a decorative rectangle impersonate a case study.
For every image in a proof-bearing position, establish:
- Provenance: company-produced, customer-supplied, licensed stock, commissioned illustration or another source;
- Represented subject: the exact person, place, product, project, stage or concept shown;
- Page implication: what a reasonable visitor may believe the visual represents in this context;
- Claim boundary: what the asset cannot establish;
- Rights and privacy owner: who is responsible for confirming permissible use;
- Staleness trigger: which change would make the visual misleading.
This is not legal advice and a content record does not replace an appropriate rights, privacy or consent review. It stops the publishing team from treating “file exists in the library” as permission to imply anything it likes.
Cropping is an editorial decision
A crop does more than change shape. It chooses which part of the evidence survives. For an atmospheric texture, that may be harmless. For an inspection photograph, process diagram or product comparison, removing the wrong detail can destroy the image’s job while preserving its visual appeal. The designer needs to know what cannot disappear:
Only then can somebody judge widescreen, square and mobile crops. This is where branding systems often become accidentally dishonest. The design system demands a consistent aspect ratio; the information demands an inconsistent frame. If every project image must become a shallow cinematic strip, important evidence at the top or bottom will eventually be amputated.
My preference is to let the image job constrain the component. Consistency should support recognition and usability, not force every visual into the same evidential shape.
Alt text cannot rescue the wrong image
Alternative text depends on the image’s purpose and context. It is not a description box waiting for SEO keywords. The W3C Web Accessibility Initiative distinguishes informative, decorative, functional, text, complex and grouped images. Its central principle is contextual: the appropriate text alternative depends on what the image does on that page. Decorative images generally need a null text alternative; functional images need the action or destination communicated; informative images need their essential information preserved. W3C’s images tutorial provides the decision guidance.
That means the same photograph can require different treatment in different contexts. A portrait beside a named biography has a different job from the same portrait used as a decorative background. A product image inside a linked card has a different functional context from the image inside the product page gallery.
Writing elaborate alt text for a generic stock photograph does not make the image useful or company-specific. Adding a service and location phrase does not repair weak provenance. Describing every visual detail can also bury the one detail a non-visual user actually needs.
Google says it uses alt text with page content and computer vision to understand image subject matter, and recommends placing images near relevant text on pages relevant to that subject. Google’s image SEO guidance supports accurate context. It does not make alt text a ranking incantation or guarantee image-search traffic. Accessibility supplies the immediate human reason to define purpose properly. Search understanding can benefit from the same honest relationship between visual and page.
Give each important visual an Image Job Card
The Image Job Card is the practical asset I use to stop meaning disappearing between marketing, design, content and development. Complete it for important, informational, functional or proof-bearing images, not necessarily every decorative flourish.
| Field | Decision to record |
|---|---|
| Page and slot | Exact page, component and location |
| Reader situation | What the person is trying to understand or do here |
| Image job | Identify, verify, compare, explain, orient, operate or decorate |
| Exact subject | What is truthfully shown |
| Page implication | What nearby copy and placement may lead a visitor to infer |
| Claim boundary | What the visual does not prove |
| Provenance and permissions | Source plus the owner of rights/privacy confirmation |
| Essential detail | What every approved crop must preserve |
| Text relationship | Which adjacent explanation gives the image meaning |
| Accessibility route | Image category and specialist responsible for final treatment |
| Delivery owner | Who produces variants, markup and loading behaviour |
| Expiry trigger | What change requires review or removal |
The card is not a sitewide spreadsheet for its own sake. It is a compact transfer record for an asset whose meaning could otherwise be guessed by several people. It can also return an uncomfortable but valuable outcome: no image required.
If the business cannot establish provenance, the visual implies unsupported proof, the essential detail cannot survive the component or the image answers no reader question, do not push it through production because the wireframe contains a rectangle.
Not sure which images on your site are proof and which are just filling rectangles? We can run the disappearance test on your key pages with you.
Optimise according to the job
Once purpose is clear, technical optimisation becomes more intelligent. An evidence-rich project photograph may need enough resolution to inspect a detail and a caption that preserves scope. A decorative background may tolerate aggressive compression, responsive cropping and no verbal alternative. A diagram may need scalable delivery, readable labels and a longer textual explanation nearby. A functional icon needs a reliable accessible name for the control rather than a description of its geometry.
Performance still matters. Heavy images can slow pages and damage the experience they were supposed to improve. Formats, dimensions, responsive sources and loading priority should reflect the actual template and use. But “make every image as small as possible” is not a strategy. The correct goal is to deliver the required information with the least unnecessary cost. Faster is valuable. Legible is valuable. Truthful is non-negotiable. The answer varies by asset because the job varies.
Do not make image count a content target
An article does not become useful because it contains a prescribed number of images. A service page does not become trustworthy because every section receives a photograph. An ecommerce product does not become persuasive because the gallery is full. Visual coverage should follow buyer uncertainty.
A product page may need multiple views because fit depends on shape, scale, finish or interface detail. A documented workflow may need process images because sequence matters. A professional service may have little genuinely visual evidence and benefit more from a sample deliverable, decision table or named method.
Forcing imagery into every slot creates stock repetition and weakens the distinction between proof and atmosphere. It also consumes design, accessibility, performance and governance work that could be spent on the assets carrying real decisions.
My standard is not visual richness. It is visual information gain: the image should add something the nearby copy cannot communicate as efficiently or credibly on its own.
Review the rendered relationship, not only the asset
An approved image can become misleading after implementation. The wrong crop may publish at a breakpoint. A caption can separate from its visual. A lazy-loaded image can fail while the surrounding claim remains. A carousel may hide controls. Text embedded in a diagram may become unreadable. A replacement asset may inherit stale alternative text or a company-specific caption. Final QA therefore needs the rendered page, not only the media-library record. Check:
The image and its delivery form one public asset even when several specialists own the work.
Make the image defend its position
Take the most prominent image on an important page and run the disappearance test. If the buyer loses nothing but atmosphere, call it decoration and treat it honestly. If the buyer loses essential information, write down that job and protect it through provenance, crop, context, accessibility and delivery. If the image quietly claims a project, person, location or result the business cannot verify, replace it or remove the implication. Then optimise it.
Image SEO should make a useful visual easier to access, understand and deliver. It should not be the process by which an arbitrary rectangle acquires a filename, six keywords and the appearance of purpose.
Good to know
FAQs
Remove the image temporarily and ask which specific identification, verification, comparison, explanation or action becomes harder. If the page only feels emptier, the image is decoration. If a buyer decision gets harder, it has an informational or functional job that must be protected.
No. Licensed stock can establish a category, create mood or support a visual identity, but it does not become evidence of your people, premises, process or completed work because the licence permits commercial use. Placement under headings like “Our projects” or “Meet the team” creates a claim the page must not make falsely.
Alt text should reflect what the image does on that page, following W3C guidance for informative, decorative and functional images. Google uses alt text with page content and computer vision to understand images, but it is not a ranking incantation, and elaborate alt text cannot make a generic stock photo useful.
As many as buyer uncertainty requires. A product may need several views because fit depends on detail; a professional service may have little genuinely visual evidence. Image count is not a content target, and forcing imagery into every slot weakens the distinction between proof and atmosphere.
Next step
Want every image on your site to earn its place?
We audit key pages with the disappearance test and Image Job Cards, separating decoration from proof before anyone touches compression or alt text.