Web Accessibility and the Role of Alt Text
Alternative text, commonly known as alt text, serves as a textual replacement for visual elements on a webpage. For individuals who use screen readers—assistive software that reads digital text aloud—alt text is the only way to understand the content and purpose of an image. When a screen reader encounters an image, it reads the alt text aloud to the user. If an image lacks alt text, the screen reader may skip it entirely or read the file name, which rarely provides useful context.
Beyond accessibility, alt text plays a critical role in Search Engine Optimization (SEO). Search engine crawlers index web content by reading text. Providing descriptive alt text helps search engines understand what an image depicts, which improves the indexing of the page and allows the image to appear in relevant image search results.
Image Specifications and Supported Formats
The generator accepts specific image file formats commonly used across modern websites. Each format serves distinct purposes in web development:
- JPG / JPEG: Ideal for photographs and complex images with gradients, offering a balance between file size and image quality.
- PNG: Best for images requiring transparency, line art, or graphics with sharp text.
- WebP: A modern format providing superior lossy and lossless compression, resulting in smaller file sizes for faster page loads.
- GIF: Used for simple graphics, flat-color illustrations, or short animations.
The tool supports files up to a maximum size of 10 MB. If you attempt to upload a file that exceeds this limit, the interface displays the error message: "That image is over 10 MB — try a smaller one.". If you upload an unsupported file format, the tool displays: "That is not a supported image. Use JPG, PNG, WebP or GIF.".
Choosing Between Concise and Detailed Descriptions
The tool offers two length options to accommodate different content requirements:
| Length Option | Target Length & Behavior | Best Use Cases |
|---|---|---|
| Concise | Aims for approximately 125 characters. | Standard inline web images, decorative elements that require context, and general product listings. |
| Detailed | Generates a longer, more comprehensive description. | Complex diagrams, charts, infographics, or images serving as primary editorial content. |
Screen readers often truncate or pause reading alt text once it exceeds a certain length. The industry standard threshold is approximately 125 characters. If the generated text exceeds this limit, the tool displays a length hint: "Over ~125 characters — some screen readers may cut it off.". This warning helps you decide whether to edit the text down or keep the longer description for complex figures.
Reviewing and Editing Generated Alt Text
While the generator provides a strong initial draft, human review is essential before publishing the text to a live website. Automated tools cannot fully understand specific organizational contexts, subjective intent, or proprietary details.
When reviewing the generated text, check for and manually correct the following elements:
- Specific Names: Identify and insert the exact names of people, locations, or unique objects.
- Brands and Logos: Ensure brand names are spelled correctly and logos are identified accurately.
- Exact Text: Verify that any text embedded within the image (such as signs, labels, or document text) is transcribed precisely.
The output field remains fully editable, allowing you to refine the wording directly within the interface before copying it. If the automatic copy function fails, the tool displays: "Could not copy — select the text and copy it manually.".
Privacy, Processing, and Daily Limits
To generate the description, your image is sent to a secure service, and the resulting text is returned immediately. The image is never stored, reused, or used for training purposes. All processing occurs on demand, and no permanent record of your image is kept.
Because the generator runs on a free daily allowance to remain accessible to everyone, it may occasionally pause if the daily limit is reached. If this occurs, the interface displays the message: "Daily limit reached — please come back tomorrow." or "The alt text generator has reached the free limit for today and is paused. It will be back tomorrow — thanks for your patience.".
Frequently Asked Questions
Is my image uploaded, and do you keep it?
Writing a description needs real computing power, so your image is sent to a secure service, described, and the text returned immediately. It is not stored, reused, or used to train anything.
How accurate is the generated alt text?
It is a strong first draft. Review it and fix anything the model cannot know from the picture alone — names, brands, logos, or exact text in the image. That is why the result stays fully editable.
How long should alt text be?
Aim for about 125 characters so screen readers read it in full — that is the Concise option. Detailed writes a longer description, handy for figure captions or a long image description.
Why does it sometimes pause?
The generator runs on a free daily allowance so it stays free to use. Once that runs out for the day it pauses, then picks back up the next day.