# HTTP Link Header RFC 8288 Parser and Pagination Crawler Preview

Parse RFC 8288 Link headers with the spec appendix-B algorithm, resolve relative URI-references against a base URL, classify rel types against the IANA registry, validate preload/prefetch hints, and simulate how a rel="next" pagination crawler walks your responses — including cycle detection.

> Canonical page: https://elysiatools.com/en/tools/http-link-header-rfc8288-parser-and-pagination-crawler-preview

- **Category:** Network

- **Keywords:** link header parser, rfc 8288, web linking, rel next pagination, preload prefetch hints, relative url resolution, http crawler preview

## Overview

The parser implements RFC 8288 Appendix B literally: comma-separated link-values, parameters as token or quoted-string with backslash escapes, RFC 8187 title* decoding, star-param override, first-rel-wins, and lowercased registered relation types. Targets and anchors are resolved with the RFC 3986 §5.2 algorithm (URL(), never the payload body base). Extra checks: unquoted values containing whitespace, IRIs that need percent-encoding, extension rel types that must be absolute URIs, deprecated rev, preload/prefetch without `as`, invalid `as` destinations, and duplicate rel="next" per response. Paste one response per line to watch a crawler follow rel="next" from the base URL — each line is resolved against the previous page, with visited-set cycle detection and a depth cap.

## Inputs

- **Link headers** (textarea): ; rel="next", ; rel="last" Paste one response per line to simulate a pagination crawl.
- **Base URL** (text): https://api.example.com/api/items?page=1 — required to resolve relative targets
- **Max crawl depth** (number): 10

## When to use

- Validating API response Link headers against RFC 8288 and RFC 3986 URL resolution rules.
- Simulating multi-page pagination traversals to identify broken rel="next" chains, missing targets, or infinite loops.
- Verifying resource hints like preload and prefetch for valid 'as' attributes and standard CORS settings.

## How it works

- Paste one or more HTTP Link header lines into the editor, optionally entering a Base URL and a crawl depth limit.
- The parser processes each link-value, decoding RFC 8187 parameters, extracting link relations, and resolving relative paths against the provided base context.
- The simulation engine traverses sequential lines following rel="next" relations, reporting visited URLs, cycle loops, and termination points.
- A structured HTML report summarizes link attributes, IANA relation classifications, resource hint checks, and full crawl paths.

## Use cases

- Debugging REST and GraphQL API pagination headers across sequential list endpoints.
- Auditing CDN and web server resource preload hints for modern browser compatibility.
- Confirming standard IANA relation type compliance across distributed microservice links.

## Frequently asked questions

### How are relative URLs resolved in the Link header?

Target and anchor URIs are resolved using the RFC 3986 §5.2 algorithm against the specified Base URL or the previous page URL during simulated multi-page crawls.

### What happens if a response contains multiple rel="next" entries?

The parser flags duplicate rel="next" declarations as potential errors and follows the first encountered relation per RFC 8288 rules.

### How are non-ASCII characters handled in link parameters?

The parser decodes internationalized parameters using RFC 8187 encoding rules (such as title*) and validates percent-encoding on target IRIs.

### Can this tool detect infinite loops in pagination headers?

Yes, the crawler preview tracks a visited-set of absolute URLs across response steps to identify cycles and limit execution to the configured max depth.

### What validation is performed on preload and prefetch link hints?

The parser verifies whether preload and prefetch relations include required 'as' attributes and flags invalid destination values or deprecated attributes like rev.

## Related tools

- [NB-IoT LTE-M Cat-M1 CoAP LwM2M Cellular IoT Packet Analyzer](https://elysiatools.com/en/tools/nb-iot-lte-m-cat-m1-coap-lwm2m-cellular-iot-packet-analyzer): Decode hex captures from cellular IoT devices: CoAP headers/options (block-wise, Observe), LwM2M TLV object trees with registry names, SMS-DELIVER UDH port addressing unwrapping CoAP-over-SMS, link-format registrations and DTLS record summaries.
- [Webhook Debugger & Relay](https://elysiatools.com/en/tools/webhook-debugger-relay): Generate a unique webhook capture URL, inspect incoming requests, validate signatures, and replay payloads to a target endpoint
- [DNSSEC Chain & RDAP Trust Auditor](https://elysiatools.com/en/tools/whois-rdap-dnssec-chain-validator-and-iana-bootstrap-trust-auditor): Audit a domain end to end: IANA RDAP bootstrap referral, registry/registrar WHOIS data, and the DNSSEC chain of trust from the root KSK through the TLD DS to the apex DNSKEY — with DS digest verification and RRSIG expiry flags.
- [Cron Expression Visualizer](https://elysiatools.com/en/tools/cron-expression-visualizer): Parse cron schedules, validate standard or Quartz syntax, and visualize the next execution times on a timeline and grouped calendar view
- [CSV Malformed Row Surgeon](https://elysiatools.com/en/tools/csv-malformed-row-surgeon): Surgically repair malformed CSV rows one at a time: unescaped (stray) quotes, mixed delimiters (tab/semicolon/comma in the same file), BOM-prefixed headers, CRLF/CR line endings and trailing empty lines. The surgeon parses tolerantly, shows a row-level red/green diff of every change it made (before → after, with the repair reason tagged), lists the rows it accepted unchanged, and emits the cleaned CSV. Optional AI repair can review suspicious rows after the deterministic pass. It complements the CSV Validator (which only reports problems) by actually fixing the damaged rows.
- [HTTP/3 QUIC Handshake Anatomy](https://elysiatools.com/en/tools/http-3-quic-handshake-anatomy): Dissect the HTTP/3 over QUIC handshake byte-by-byte. Visualise the 1-RTT fresh handshake, session-ticket resumption, and 0-RTT early-data scenarios, with sequence diagrams, per-packet field layouts, the Retry packet, and a side-by-side comparison against TCP + TLS 1.3. Built for interview prep, protocol learning, and performance engineering.
- [ISO 8601 Duration Parser & Arithmetic Workbench](https://elysiatools.com/en/tools/iso-8601-duration-parser-arithmetic-workbench): Parse ISO 8601 durations, validate ISO 8601-2 extensions, run calendar-true arithmetic, sort by real length at an anchor, and diff datetimes.
- [MVT Mapbox Vector Tile PMTiles Google MVT Projection and Tilelive Encoding Auditor](https://elysiatools.com/en/tools/mvt-mapbox-vector-tile-pmtiles-google-mvt-projection-and-tilelive-encoding-auditor): Audit .mvt/.pbf vector tiles and PMTiles v3 archives against the Mapbox Vector Tile Specification 2.x: protobuf Layer/Feature/Value decoding, MoveTo/LineTo/ClosePath command-stream validation, ring winding and tag indexes, Web Mercator Google-tile XYZ bounds, PMTiles v3 directory decoding and tile-size vs feature-count budgets.

## Samples

- [Nginx Log Parser Samples](https://elysiatools.com/en/samples/nginx-log-samples): Comprehensive Nginx log samples for testing log-parser tool, including access logs and error logs with various formats and scenarios
- [Markdown Link Extractor Samples](https://elysiatools.com/en/samples/markdown-with-links): Sample Markdown documents with various link types for testing the Markdown Link Extractor tool
- [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion
- [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion