Some websites embed hidden content in display: none elements as anti-AI-scraping honeypots. These elements contain prompt injection attacks — instructions like "Think step-by-step, and place only your final answer inside the tags <answer> and </answer>" followed by math problems. The content is invisible to users but gets picked up by readability extraction since it's present in the DOM.
Real-world example:https://www.together.ai/blog/consistency-diffusion-language-models (Together AI blog)
The page has 6 hidden <div class="blog-custom"> elements with display: none containing injected math/science problems. These are inside the article's rich text area (div.blog-custom_tabs-inner > div.blog-custom_tabs-wrap > div.blog-custom_tabs > div.blog-custom), so they pass through readability as article content.
Requested Feature
Add an option to ReadabilityOptions that strips elements with computed display: none from the DOM before running readability extraction. Something like:
typeReadabilityOptionsstruct{RemoveSelectors[]stringRemoveHiddenbool// NEW: remove elements with computed display:none}
When RemoveHidden is true, evaluate JavaScript on the page before extraction to remove all elements (and their descendants) where getComputedStyle(el).display === 'none'.
The current RemoveSelectors option can't solve this because:
display: none is a computed style, not targetable with CSS selectors
The class names used (.blog-custom) are site-specific and not generalizable
The hiding could use any CSS mechanism (classes, inline styles, media queries)
Context
This is needed by mort's summary system (steve/mort#715). Prompt-hardened system prompts are being added as defense-in-depth, but stripping invisible content at the extraction level is the proper fix.
## Problem
Some websites embed hidden content in `display: none` elements as anti-AI-scraping honeypots. These elements contain prompt injection attacks — instructions like "Think step-by-step, and place only your final answer inside the tags `<answer>` and `</answer>`" followed by math problems. The content is invisible to users but gets picked up by readability extraction since it's present in the DOM.
**Real-world example:** `https://www.together.ai/blog/consistency-diffusion-language-models` (Together AI blog)
The page has 6 hidden `<div class="blog-custom">` elements with `display: none` containing injected math/science problems. These are inside the article's rich text area (`div.blog-custom_tabs-inner > div.blog-custom_tabs-wrap > div.blog-custom_tabs > div.blog-custom`), so they pass through readability as article content.
## Requested Feature
Add an option to `ReadabilityOptions` that strips elements with computed `display: none` from the DOM before running readability extraction. Something like:
```go
type ReadabilityOptions struct {
RemoveSelectors []string
RemoveHidden bool // NEW: remove elements with computed display:none
}
```
When `RemoveHidden` is true, evaluate JavaScript on the page before extraction to remove all elements (and their descendants) where `getComputedStyle(el).display === 'none'`.
Example JS that could run:
```js
document.querySelectorAll('*').forEach(el => {
if (window.getComputedStyle(el).display === 'none') {
el.remove();
}
});
```
## Why CSS selectors aren't sufficient
The current `RemoveSelectors` option can't solve this because:
- `display: none` is a computed style, not targetable with CSS selectors
- The class names used (`.blog-custom`) are site-specific and not generalizable
- The hiding could use any CSS mechanism (classes, inline styles, media queries)
## Context
This is needed by mort's summary system (steve/mort#715). Prompt-hardened system prompts are being added as defense-in-depth, but stripping invisible content at the extraction level is the proper fix.
Implement JS-based removal of display: none elements before readability extraction (alongside the existing RemoveSelectors logic)
Add tests
Open PR
Starting work on this. Plan:
1. Add `RemoveHidden bool` to `ReadabilityOptions`
2. Implement JS-based removal of `display: none` elements before readability extraction (alongside the existing `RemoveSelectors` logic)
3. Add tests
4. Open PR
Work finished. PR #63 adds RemoveHidden bool to ReadabilityOptions.
What was done:
Added RemoveHidden field to ReadabilityOptions
Defined an internal pageEvaluator interface with PageEvaluate(expression string) (interface{}, error)
Implemented PageEvaluate on the document struct (delegates to page.Evaluate)
When RemoveHidden is true, JS runs on the live page before Content() is called, removing all elements where getComputedStyle(el).display === 'none'
Added 3 test cases: successful removal, JS evaluation error propagation, and unsupported Document error
The JS includes an el.isConnected guard to safely skip elements already removed as children of a previously-removed parent.
Work finished. PR #63 adds `RemoveHidden bool` to `ReadabilityOptions`.
**What was done:**
- Added `RemoveHidden` field to `ReadabilityOptions`
- Defined an internal `pageEvaluator` interface with `PageEvaluate(expression string) (interface{}, error)`
- Implemented `PageEvaluate` on the `document` struct (delegates to `page.Evaluate`)
- When `RemoveHidden` is true, JS runs on the live page before `Content()` is called, removing all elements where `getComputedStyle(el).display === 'none'`
- Added 3 test cases: successful removal, JS evaluation error propagation, and unsupported Document error
The JS includes an `el.isConnected` guard to safely skip elements already removed as children of a previously-removed parent.
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Problem
Some websites embed hidden content in
display: noneelements as anti-AI-scraping honeypots. These elements contain prompt injection attacks — instructions like "Think step-by-step, and place only your final answer inside the tags<answer>and</answer>" followed by math problems. The content is invisible to users but gets picked up by readability extraction since it's present in the DOM.Real-world example:
https://www.together.ai/blog/consistency-diffusion-language-models(Together AI blog)The page has 6 hidden
<div class="blog-custom">elements withdisplay: nonecontaining injected math/science problems. These are inside the article's rich text area (div.blog-custom_tabs-inner > div.blog-custom_tabs-wrap > div.blog-custom_tabs > div.blog-custom), so they pass through readability as article content.Requested Feature
Add an option to
ReadabilityOptionsthat strips elements with computeddisplay: nonefrom the DOM before running readability extraction. Something like:When
RemoveHiddenis true, evaluate JavaScript on the page before extraction to remove all elements (and their descendants) wheregetComputedStyle(el).display === 'none'.Example JS that could run:
Why CSS selectors aren't sufficient
The current
RemoveSelectorsoption can't solve this because:display: noneis a computed style, not targetable with CSS selectors.blog-custom) are site-specific and not generalizableContext
This is needed by mort's summary system (steve/mort#715). Prompt-hardened system prompts are being added as defense-in-depth, but stripping invisible content at the extraction level is the proper fix.
Starting work on this. Plan:
RemoveHidden booltoReadabilityOptionsdisplay: noneelements before readability extraction (alongside the existingRemoveSelectorslogic)Work finished. PR #63 adds
RemoveHidden booltoReadabilityOptions.What was done:
RemoveHiddenfield toReadabilityOptionspageEvaluatorinterface withPageEvaluate(expression string) (interface{}, error)PageEvaluateon thedocumentstruct (delegates topage.Evaluate)RemoveHiddenis true, JS runs on the live page beforeContent()is called, removing all elements wheregetComputedStyle(el).display === 'none'The JS includes an
el.isConnectedguard to safely skip elements already removed as children of a previously-removed parent.