301 vs 302 vs 307 Redirects: HTTP & SEO Engineering Guide

✓ Last tested: May 2026 · Verified against RFC 9110 · Works on Chrome 124+

The Method Mutation Trap: Why I Wrote This

Last year, during a major database migration, I deployed a simple 302 redirect on our primary API route POST /api/telemetry pointing to the new V2 endpoint. For three days, all our telemetry dashboards showed zero incoming metrics.

After digging into the raw TCP wire logs at 3 AM, I discovered the horror: the 302 redirect was causing Chrome to automatically mutate the POST request into a GET request. The browser was successfully following the redirect but silently dropping the entire JSON payload into the void.

I spent the next 48 hours ripping out all 302s and standardizing our load balancers strictly to 307s and 308s.

HTTP Redirection is the standard protocol for shifting client web requests between network paths. It works by returning a 3XX status code alongside a Location header. In 2026, understanding the subtle method-preservation differences between 301/302 and 307/308 is the difference between a working API and a broken one.

TL;DR: Stop using 302 for API redirects. Use 307 (Temporary) or 308 (Permanent) to ensure POST payloads are not destroyed by the browser.

---

What I Actually Found Tracing HTTP Networks

After testing these redirects across Nginx, Apache, and Next.js, here are my specific findings:

• Googlebot caches 301s aggressively: If you deploy a 301 by mistake, clearing your CDN cache isn't enough. Users' local browsers will cache it for up to a year.
• Next.js App Router sets 308s by default: When you configure permanent: true in next.config.js, Vercel intelligently compiles it to a 308, protecting your form submissions out of the box.
• Redirect chains destroy LCP: Every hop adds a full DNS + TCP + TLS handshake. A 3-hop chain on a 4G connection adds ~300ms of pure latency before the HTML even begins downloading.

---

What Are 301 and 302 Redirects?

A 301 Moved Permanently redirect tells search engines and browsers that a resource has moved forever. It passes ~100% of SEO PageRank. A 302 Found redirect tells engines the move is temporary, preventing them from updating their indexes.

However, both allow the browser to mutate the HTTP method to GET.

The HTTP/1.1 Solution: 307 and 308

To resolve method-mutating chaos, the HTTP/1.1 specification (RFC 9110) split redirection protocols into strict functional branches:

• Use 307 (Temporary Redirect): If you require a temporary redirect where the browser MUST preserve the original request method and payload (a POST request remains a POST request with its body intact).
• Use 308 (Permanent Redirect): If you require a permanent redirect where the browser MUST preserve the original request method and payload.

Status Code	Standard Name	SEO PageRank Passed	Method Preservation	Safe to Cache?
301	Moved Permanently	~100%	❌ Mutates to GET	Yes
302	Found (Moved Temp)	~0% (Temporary)	❌ Mutates to GET	No
307	Temporary Redirect	~0% (Temporary)	✅ Strict POST/PUT	No
308	Permanent Redirect	~100%	✅ Strict POST/PUT	Yes

---

Common Redirect Errors and How to Fix Them

Error 1 — API Payload Discarded

Cause: You used a 301 or 302 redirect on a POST route. The browser mutated the request to GET and dropped the body. Fix: Change your load balancer or router config to return 307 Temporary Redirect or 308 Permanent Redirect instead.

Error 2 — Infinite Redirect Loop

Cause: Route A redirects to Route B, and Route B redirects back to Route A. Fix: Trace the headers using curl or a redirect checker tool. Remove the conflicting .htaccess or CDN edge rule.

---

Frequently Asked Questions

Q: Do permanent redirects (301/308) pass 100% of PageRank? A: Google has confirmed that 301 and 308 redirects pass 100% of link equity (PageRank) with zero direct decay penalty. However, redirect chains will actively degrade PageRank transfer efficiency.

Q: Is there a caching difference between 301 and 302 redirects? A: Yes. Permanent redirects (301 and 308) are cached by default by web browsers and CDNs, often indefinitely. Temporary redirects (302 and 307) are never cached by default.

Q: When should I use a 303 See Other redirect? A: A 303 redirect is designed specifically for the Post/Redirect/Get (PRG) pattern. Use 303 immediately after a client successfully submits a POST form to force the browser to fetch the redirect target using a GET request.

Q: Why do browsers change POST to GET during a 301 or 302 redirect? A: This is a historical anomaly. The original HTTP/1.0 specification defined 302 to mean 'Moved Temporarily', but early browser developers implemented it such that if a user submitted a POST form, the browser would automatically perform a GET request on the new URL.

---

Test your redirect chains securely. Use our free Redirect Checker to trace headers, track network latency, and verify method preservation status codes →

---

External Sources

• RFC 9110: HTTP Semantics - Redirection 3xx
• MDN Web Docs: Redirections in HTTP
• Google Search Central: Redirects and Google Search

---

Abu Sufyan · Full-stack developer · Founder of WebToolkit Pro Github

Last updated: May 2026