The htaccess to Nginx Converter translates a deliberately narrow subset of Apache .htaccess directives into review-ready Nginx lines, runs entirely in your Mac browser, and surfaces every condition or unsupported rule with its original line number rather than guessing. Four patterns are mapped directly: a supported RewriteRule with a bracketed flag list of L, R, R=301 or R=302, Options -Indexes, a local ErrorDocument 404 path, and a quoted X-Robots-Tag Header set value that becomes an add_header line. Apache patterns in document-root .htaccess normally match the path after the directory prefix has been removed, so they typically begin with a caret and no leading slash; the converter inserts that leading slash for Nginx, where rewrite patterns see a URI starting with /. Anything conditional, syntactically ambiguous or unfamiliar stops the conversion for that rule and is reported, because a plausible-looking but non-equivalent Nginx line is more dangerous than an explicit manual task. The output is a fragment, not a complete nginx.conf. You assemble it into the correct server or location block, back up the active configuration, run nginx -t, and test on staging before any reload.
Mac browser setup: no install, no upload
You do not need Homebrew, Nginx installed locally, or a terminal session to start a migration on macOS. The htaccess to Nginx Converter runs in any modern Mac browser, processes your pasted excerpt locally, and never sends the input to Lizely. Open Safari, Chrome, Firefox or Arc, navigate to the converter page, and you are ready. If you maintain a development Nginx on the Mac itself for staging, keep a separate terminal window open so you can back up the active configuration and run nginx -t once the fragment is ready. Local Nginx on macOS is commonly installed through Homebrew, runs as a launchd service, and reads configuration from a path such as /opt/homebrew/etc/nginx/nginx.conf or /usr/local/etc/nginx/nginx.conf depending on the architecture.
Working in a version-controlled folder is the safest pattern. Save your source .htaccess excerpt as htaccess.txt inside a migration branch, paste the focused lines into the converter, and commit only what you have reviewed. The converter does not crawl your site, does not execute Nginx, and does not require AllowOverride or filesystem access. Treat it as an inventory assistant that emits a draft for human review.
How to convert htaccess to Nginx on Mac: a step-by-step workflow
- Open the htaccess to Nginx Converter in your Mac browser and copy a focused, document-root .htaccess excerpt into the input area. Do not paste the whole legacy file at once.
- Click convert and read the emitted output line by line. Count the converted lines and the warnings.
- For every warning, note the original line number shown in the result, then open the Apache mod_rewrite introduction and the Nginx rewrite module documentation to decide how to migrate that rule by hand.
- Save the emitted fragment as nginx-fragment.conf in your migration folder so the review trail is preserved.
- Open your real nginx.conf or an included file in a text editor with syntax highlighting. Place each reviewed line in the correct context: rewrite rules and error_page belong inside the relevant server or location block, and the headers module must be loaded if you use add_header.
- Back up the active configuration with a timestamped copy, then assemble the fragment in place. Run nginx -t to validate the full assembled configuration before any reload.
- Test representative requests on staging or during a reversible maintenance window. Confirm the response Location header with curl -I rather than relying on the browser address bar alone.
- Reload Nginx only after the test set passes. Keep the backup and the open recovery session available until production traffic is verified.
What the converter translates and what it deliberately ignores
The supported rewrite form contains exactly one RewriteRule with a pattern, a substitution and a bracketed flag list drawn from the documented set L, R, R=301 and R=302. A permanent Apache redirect becomes the Nginx permanent flag, a temporary redirect becomes redirect, and an internal last rule becomes last. Patterns in document-root .htaccess normally match a path after the directory prefix has been removed, so they commonly begin with a caret and no slash; the converter inserts that leading slash because Nginx rewrite patterns see a URI that starts with /. This is a documented scope assumption, not a universal transformation for nested .htaccess files, Alias mappings or location-specific blocks.
| Apache form in the pasted excerpt | Tool behaviour | Next step on your Mac |
|---|---|---|
| RewriteRule pattern sub [L] | Emitted as a last rewrite with leading slash inserted | Place in the right server or location block |
| RewriteRule pattern sub [R=301] | Emitted as a permanent redirect | Test with the temporary flag first if practical |
| RewriteRule pattern sub [R] | Emitted as a temporary redirect | Place in the right context and validate |
| RewriteRule with QSA, END, F, G, B, NC and similar flags | Reported with line number, no output emitted | Migrate manually after reading both manuals |
| RewriteCond followed by a RewriteRule | Both lines reported, no output emitted | Re-evaluate variables, ordering and server context |
| RewriteRule with a single-dash substitution | Reported with line number, no output emitted | Often combines with access flags, migrate manually |
| Options -Indexes | Emitted as autoindex off | Place inside the location to protect |
| ErrorDocument 404 /404.html | Emitted as error_page 404 /404.html | Place inside the relevant context per the nginx core error_page docs |
| X-Robots-Tag Header set "value" | Emitted as add_header X-Robots-Tag "value" | Place in the right context with the headers module loaded |
RewriteCond lines are never translated automatically. Apache conditions can inspect HTTPS state, host names, files, directories, query strings, headers and captured groups, and their evaluation order and the server architecture matter. When a RewriteRule follows a condition, the converter suppresses the rule as well, rather than emitting an unconditional redirect that could change traffic, create a loop or expose a route. The Apache no-substitution target represented by a single dash is also withheld, because it often combines with flags that alter access or processing without changing the URI and a literal dash is not a safe Nginx replacement. Other status codes, external error documents, conditional headers, environment variables and directive containers require manual migration. For the underlying semantics of the original Apache rules, the Apache mod_rewrite introduction is the right starting point.
From browser output to a working Nginx configuration on your Mac
The fragment does not create an http, server or location block, does not choose a listen port, does not set server_name, does not configure TLS, does not locate a document root, does not preserve PHP routing, does not forward a proxy, and does not define logs. A line can be syntactically valid yet wrong for its context, so context selection is part of the migration. Place rewrite rules in the server block for whole-site redirects, or in a location block when the rule targets a subset of paths. Place add_header inside the context that actually serves the response, because Nginx inheritance is different from Apache's directory walk.
On a Mac, validate with nginx -t before reloading. The command reads the assembled configuration, parses every include, and reports the first syntax error or unknown directive it finds. If you use add_header for X-Robots-Tag, confirm that the headers module is loaded by checking the configure arguments for with-http_headers_module. If the module is missing, the directive will fail at reload and your staging tests will return 500 errors. Once nginx -t is clean, reload with nginx -s reload and verify representative URLs with curl -I on staging.
Permanent versus temporary redirects: a Mac checklist before reloading
Permanent redirects deserve extra care because browsers and intermediaries cache them. Start with temporary redirects in a controlled environment if practical, then switch to permanent only after testing old paths, new paths, query strings, alternate hosts and HTTPS behaviour. Confirm the response Location header with curl -I rather than relying on the browser address bar, because the address bar can follow a chain of redirects and hide the first hop. Capture the raw headers for at least one redirect per RewriteRule so the audit trail is complete. A failed reload or redirect loop can take a public site offline, and a cached permanent redirect can keep users on the wrong path even after the configuration is fixed.
When to step back from the converter and migrate manually
If the source excerpt contains authentication, authorization, hotlink protection, proxy logic, CMS front-controller rules or complex conditions, treat the migration as engineering work rather than bulk text replacement. Apache and Nginx use different request-processing models. Apache .htaccess is discovered through directories and may be disabled by AllowOverride; Nginx reads centralized configuration and chooses server and location contexts before rewrite processing. Even identical regular expressions can behave differently because the string being matched, escaping, query handling and loop behaviour differ. Use the converter as an inventory assistant on a focused excerpt, resolve every warning manually, assemble the result in a version-controlled Nginx file, and validate it on staging. The tool will not pretend that an .htaccess migration is a single paste, and that is the safer stance for any production migration on macOS or anywhere else.
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