How to write alt text for SEO
Alt text is the sentence a screen reader speaks instead of your image, and the sentence Google Images reads to understand it. Most small business sites get it wrong in the same two ways, blank, or stuffed with keywords. Here is how to write it properly, with real before/after examples for product photos, blog images and logos.
Alt text, short for alternative text, is a short description you attach to every image on a page. Its first job has nothing to do with SEO: it is read aloud by screen readers for people who cannot see the image, and it displays in place of the image if it fails to load on a slow connection.
Its second job is search. Google cannot see a photo the way you can. It reads the filename, the surrounding text, and the alt attribute to work out what the image shows and whether it is worth surfacing in Google Images or associating with the page's topic. Get the wording right and you gain accessibility and a small, genuine search benefit at the same time, for the cost of one sentence per image.
This is deliberately the basics version. If you want the technical side, compression, lazy-loading, responsive image formats, that belongs in a technical SEO guide, not here. This one is only about the words.
The two mistakes almost every site makes
The first mistake is leaving alt text blank. Check your own site's images right now, most content management systems let an image go live with an empty alt attribute unless you fill it in deliberately, and most people never do. A blank alt attribute means a screen reader either skips the image entirely or reads out the filename, IMG_20260304_142207.jpg, which is useless to a blind visitor and useless to Google.
The second mistake, common once someone learns alt text 'matters for SEO', is stuffing it with keywords: 'momo Kathmandu best momo shop momo delivery cheap momo Nepal'. This is not a description of anything, it is a list, and it is exactly the kind of manipulation Google's spam guidance targets. It also insults the screen reader user it was supposed to help. If you would not say the sentence out loud to a person, do not write it as alt text.
The one-sentence rule
Write alt text as if you are describing the photo, out loud, to a friend on the phone who cannot see it. That single mental trick fixes almost every alt text problem at once, because it naturally rules out keyword lists, and it naturally makes you specific.
Keep it short, roughly 125 characters is a common practical limit before some screen readers cut it off, so say the useful part first. Do not start with 'image of' or 'photo of', the screen reader already announces it as an image, that phrase just wastes the first two words of a short sentence.
- Describe what matters in the image for that context, not everything visible.
- Be specific: colour, item, setting, action, rather than a generic category.
- Skip 'image of' and 'picture of', screen readers already say this.
- If the image is purely decorative, a background swirl, a spacer, it is fine to leave alt empty (alt="") so the screen reader skips it cleanly, that is a valid choice, not a mistake, when nothing in the image adds information.
Before and after: product photos
A pashmina shop selling online, photo of a folded shawl on a wooden table.
Bad: 'IMG_8834.jpg' (blank, or the raw filename).
Also bad: 'pashmina nepal buy pashmina online cheap pashmina shawl kathmandu'.
Good: 'Hand-woven maroon pashmina shawl, 100% cashmere, folded on a wooden table.'
The good version tells a screen reader user exactly what the item looks like, and it tells Google Images the specific product, colour and material rather than a keyword pile that could describe any of two hundred competing listings.
A second product, a pair of hiking boots on a trekking gear site.
Bad: 'boots.jpg'.
Good: 'Brown leather trekking boots with ankle support, size 42, on a rocky trail background.'
Before and after: blog and article images
A blog post about a trek, with a photo of a suspension bridge on the trail.
Bad: 'nepal trekking annapurna base camp trek guide 2026 best trek'.
Good: 'Swaying suspension bridge over the Modi Khola river on the Annapurna Base Camp trail.'
The good version matches what a reader searching Google Images for 'Annapurna suspension bridge' is actually looking for, and it reinforces the page's topic to Google without repeating the page's target keyword phrase word for word, which is what the bad version is really trying, badly, to do.
A screenshot in a how-to article, say a guide about filling a government form.
Bad: (blank alt text on a screenshot).
Good: 'Screenshot of the Nagarik App showing the citizenship certificate application form, with the date of birth field highlighted.'
For a screenshot, describe what the reader needs to see in it to follow the instructions, not just 'screenshot of app'.
Logos, icons and infographics
A site logo in the header should generally use alt text with the business name, for example alt="Everest Momo House logo", since that is genuinely what a screen reader user needs to know at that point on the page.
A small decorative icon next to a heading, like a checkmark bullet or a divider line, usually carries no information on its own and can reasonably have alt="" so it is skipped rather than announced awkwardly as 'icon' or 'graphic'.
An infographic or chart is the one case where a single sentence is not enough. Give it a short alt text summarising what it shows, for example alt="Chart showing Nepal's mobile internet subscribers rising from 2020 to 2025", and then put the full data or takeaway in the surrounding text or a caption, since alt text is not the place for a paragraph of statistics.
Filenames still matter, just less
Before you even get to alt text, rename the file itself. `pashmina-maroon-cashmere-shawl.jpg` gives Google a second, independent signal about the image, whereas `IMG_8834.jpg` gives it nothing. It takes ten seconds per image when you are uploading anyway, and it is one of those small compounding habits that costs nothing and never actively hurts you.
Key takeaways
- ✓Write alt text as one specific sentence describing the image out loud to someone who cannot see it.
- ✓Never leave alt text blank on a meaningful image, and never stuff it with a keyword list.
- ✓Purely decorative images can use alt="" on purpose, so a screen reader skips them cleanly.
- ✓Skip 'image of' or 'picture of', a screen reader already announces the element as an image.
- ✓Rename image files descriptively before upload; it is a small, free signal alongside the alt text itself.
Explore the data behind this guide
How to Write Alt Text for SEO, FAQ
What is alt text used for?+
Primarily accessibility: screen readers read it aloud for visitors who cannot see the image, and it displays as fallback text if the image fails to load. It is also read by search engines to understand what an image shows, which is its secondary, smaller SEO role.
Does alt text directly improve rankings?+
It is a minor signal, mainly useful for Google Images and for reinforcing what a page is about. It will not fix a page that otherwise fails to answer the search query. Its bigger, more reliable payoff is accessibility, and writing it well as a side effect helps search engines too.
How long should alt text be?+
Short and specific. A practical target is under roughly 125 characters, since some screen readers cut off longer text. Say the useful part of the description first, in one plain sentence.
Should every image have alt text?+
Every meaningful image should. Purely decorative images, spacers, dividers, background flourishes, can legitimately use an empty alt attribute (alt="") so a screen reader skips them instead of announcing something unhelpful like 'icon' or 'graphic'.
Is keyword-stuffed alt text bad for SEO?+
Yes. A string of unrelated keywords instead of a real description reads as manipulation, works against you the way keyword stuffing anywhere else on a page does, and actively harms the screen reader users alt text exists to serve in the first place.
Related guides
Sources & data note
This guide describes documented practice from Google Search Central's image SEO guidance and the W3C Web Accessibility Initiative's alt text decision tree, both cited above. The worked before/after examples for a pashmina shop, trekking boots, a trek blog photo and a government-form screenshot are our own illustrative writing to demonstrate technique, not figures or case studies drawn from a source. Guides are written from primary sources, Nepali government departments, operators, park authorities and standards bodies, and each guide lists the sources used for its own facts. Rules, fees and prices in Nepal change; treat figures as current at the review date shown on each guide and verify anything money- or visa-critical with the issuing authority before you rely on it.