---
title: 🔍 How Google Interprets robots.txt (REP)
description: "Google’s crawlers follow the **Robots Exclusion Protocol (REP)** to check which parts of a website they can crawl. ### **📌 What robots.txt Does** - It tells **crawlers (like Googlebot)** which parts of the site they can or cannot crawl. **Example:**…"
url: "https://fsidm.in/knowledge/seo/how-google-interprets-robots-txt/"
updated: "2025-08-18"
category: SEO
---

# 🔍 How Google Interprets robots.txt (REP)

Google’s crawlers follow the **Robots Exclusion Protocol (REP)** to check which parts of a website they can crawl.

### **📌 What robots.txt Does**

- It tells **crawlers (like Googlebot)** which parts of the site they can or cannot crawl.

**Example:**
User-agent: \*

Disallow: /private/

User-agent: Googlebot

Allow: /includes/

Sitemap: https://example.com/sitemap.xml

### **📍 File Location Rules**

- Must be placed in the **root directory** of the site:

  - https://example.com/robots.txt ✅
  - https://example.com/pages/robots.txt ❌
- Applies only to **that specific host, protocol, and port**.

  - https://example.com/robots.txt → applies to https://example.com/ only.
  - https://m.example.com/robots.txt → separate rules for mobile subdomain.

### **📏 Google’s Key Interpretations**

1. **Case-Sensitive URL**
   - /Private/ ≠ /private/ (URLs are treated as exact matches).
2. **Allow vs Disallow Priority**
   - Google applies the **most specific rule** to a path.

Example:

Disallow: /includes/

Allow: /includes/css/

-  → CSS inside /includes/css/ will still be crawled.

1. **Comments (****#****) Are Ignored**
   - Use # for explanations in file (doesn’t affect crawling).
2. **Google Requires Resources**
   - Don’t block important .css or .js if they are needed to render your pages properly.
3. **Sitemap Tag is Optional**
   - Adding Sitemap: https://example.com/sitemap.xml helps Google discover pages faster.

**⚠️ What robots.txt Does NOT Do**

- ❌ **Does not hide content from search results**
  - Blocked URLs can still appear if other sites link to them.
  - Use noindex meta tag or password-protection to fully hide.
- ❌ **Not security** → It’s public. Anyone can see your robots.txt.

💡 **FSIDM Quick Tip for Students & Site Owners:** Think of robots.txt as a **traffic cop** — it directs crawlers, but it doesn’t lock doors. If you need real privacy, use **authentication or noindex**.

## **📌 Valid robots.txt URL Rules (Google’s View)**

The robots.txt file only applies to **the exact protocol, domain/subdomain, and port** it’s hosted on.

| **Robots.txt Location** | **Valid For** | **Not Valid For** |
| --- | --- | --- |
| https://example.com/robots.txt | https://example.com/ | https://other.example.com/, http://example.com/, https://example.com:8181/ |
| https://www.example.com/robots.txt | https://www.example.com/ | https://example.com/, https://shop.www.example.com/ |
| https://example.com/folder/robots.txt | ❌ Crawlers don’t check subdirectories | All |
| https://www.exämple.com/robots.txt | https://www.exämple.com/, https://xn--exmple-cua.com/ | https://www.example.com/ |
| ftp://example.com/robots.txt | ftp://example.com/ | https://example.com/ |
| https://212.96.82.21/robots.txt | https://212.96.82.21/ | https://example.com/ |
| https://example.com:443/robots.txt | https://example.com/, https://example.com:443/ | https://example.com:444/ |
| https://example.com:8181/robots.txt | https://example.com:8181/ | https://example.com/ |

💡 **FSIDM Tip**: Each subdomain needs its **own robots.txt** if you want to control crawling separately.

## **⚡ Handling HTTP Status Codes for robots.txt**

Google treats robots.txt responses differently based on status code:

| **HTTP Code** | **Google’s Behavior** |
| --- | --- |
| **2xx (Success)** | Reads and applies rules normally. |
| **3xx (Redirects)** | Follows up to 5 hops → then treats as **404**. |
| **4xx (Client Errors)** | Treated as **no robots.txt** (full crawl allowed), except 429 (rate limit). |
| **5xx (Server Errors)** | - First 12h: Stops crawling.- Next 30 days: Uses cached version if available.- After 30 days: If site available → crawls as if no robots.txt. |
| **DNS/Network Errors** | Treated as 5xx. |

## **⏱ Caching Rules**

- Google caches robots.txt for **up to 24 hours**.
- May cache longer if site is unreachable.
- Can refresh manually via **Search Console robots.txt tester**.

**📏 Format & Size Rules**

- Must be **UTF-8 encoded plain text**.
- Max size: **500 KiB** (content after that is ignored).
- Invalid lines (e.g., HTML, bad encoding) are ignored.

💡 **FSIDM Takeaway for Students & SEO Managers**:
👉 Correct **location, format, and encoding** are just as important as the rules themselves.
👉 Always test robots.txt in **Search Console** after uploading to avoid indexing issues.

## **🛠 Robots.txt Syntax Basics**

- Format:

<field>:<value>   # optional comment

- Spaces are **optional** but recommended for readability.
- # starts a comment (ignored by crawlers).

## **📌 Supported Fields (Google)**

| **Field** | **Purpose** | **Example** |
| --- | --- | --- |
| user-agent | Specifies the crawler the rules apply to | User-agent: Googlebot |
| disallow | Path **not allowed** to crawl | Disallow: /private/ |
| allow | Path **allowed** to crawl (overrides disallow) | Allow: /private/public-page.html |
| sitemap | Location of sitemap(s) | Sitemap: https://example.com/sitemap.xml |

❌ Fields like crawl-delay are **not supported** by Google.

## **🔍 Path Rules**

- Paths are **case-sensitive**. (/File.asp ≠ /file.asp)
- Paths must start with / (root relative).
- Wildcards supported:

  - \* matches any sequence of characters.
  - $ matches end of URL.

## **🧠 User-Agent Selection Logic**

Google picks **the most specific group** for the crawler:

- **Example**:

User-agent: googlebot-news   # Group 1

User-agent: \*                # Group 2

User-agent: googlebot        # Group 3

- Googlebot-News → Group 1
- Googlebot → Group 3
- Other Google bots → Group 2

📌 **Order in file doesn’t matter**. Google groups all relevant rules for a user agent internally.

## **📂 Grouping Rules**

Multiple user-agents can share rules:

User-agent: e

User-agent: f

Disallow: /g

→ Both e and f follow /g restriction.

## **📜 Example of Correct Syntax**

# Block all bots from /private/

User-agent: \*

Disallow: /private/

# Allow Googlebot access to /private/reports/

User-agent: Googlebot

Allow: /private/reports/

# Add sitemap location

Sitemap: https://example.com/sitemap.xml

💡 **FSIDM Practical Tip for Students**

- **Test in Search Console** after every change.
- **Keep rules minimal** → complex rules increase errors.
- Always combine Disallow + Allow smartly for sections.

## **🚦 URL Matching Based on Path Values in robots.txt**

Google uses the **path part** of a URL (after domain name) to decide if a robots.txt rule applies. It compares this path to the **allow** and **disallow** rules.

### **🎯 Key Wildcards Supported:**

| **Wildcard** | **Meaning** | **Example Match** |
| --- | --- | --- |
| \* | Matches **0 or more** characters | /fish\* matches /fish.html, /fishheads, etc. |
| $ | Matches **end of URL** | /\*.php$ matches /index.php but not /index.php?x=1 |

### **📌 Examples of Matching Rules**

| **Rule** | **Matches** | **Doesn’t Match** |
| --- | --- | --- |
| / | The root and everything below it (whole site) | — |
| /fish | /fish, /fish.html, /fish/salmon.html, /fish.php?id=anything | /Fish.asp (case-sensitive), /catfish, /desert/fish |
| /fish/ | Anything **inside** /fish/ folder, e.g. /fish/salmon.htm, /fish/?id=anything | /fish (without slash), /fish.html |
| /\*.php | Any URL containing .php, e.g. /index.php, /folder/filename.php?params | /windows.PHP (case sensitive) |
| /\*.php$ | URLs **ending exactly** with .php e.g. /file.php, /folder/file.php | /file.php5, /file.php?param |
| /fish\*.php | URLs containing /fish followed by .php somewhere, e.g. /fish.php, /fishheads/catfish.php | /Fish.PHP (case sensitive) |

### **⚖️ Order of Precedence — Which Rule Wins?**

- Google uses the **most specific** (longest matching) rule for a URL.
- If there are conflicting rules, Google applies the **least restrictive** rule (i.e., allows crawling if possible).

### **🔥 Real-World Examples**

| **URL** | **Rules** | **Which Rule Applies?** | **Why?** |
| --- | --- | --- | --- |
| https://example.com/page | allow: /pdisallow: / | allow: /p | /p is more specific than / |
| https://example.com/folder/page | allow: /folderdisallow: /folder | allow: /folder | In conflict, Google picks **least restrictive** rule |
| https://example.com/page.htm | allow: /pagedisallow: /\*.htm | disallow: /\*.htm | Longer, more specific disallow rule applies |
| https://example.com/page.php5 | allow: /pagedisallow: /\*.ph | allow: /page | Least restrictive rule wins |
| https://example.com/ | allow: /$disallow: / | allow: /$ | $ means exact root, more specific |
| https://example.com/page.htm | allow: /$disallow: / | disallow: / | allow: /$ only matches root URL, not /page.htm |

### **💡 FSIDM Pro Tip**

When writing rules:

- Use **/folder/** to block a directory’s content only.
- Use **/file.ext** to block specific files.
- Use wildcards \* and $ wisely to cover patterns.
- Always test your robots.txt with Google Search Console to verify rule behavior!