Translate htaccess to nginx by converting a focused, explicitly supported .htaccess excerpt into review-ready Nginx directive lines, resolving every warning, and validating the full configuration before reload. The htaccess to Nginx Converter is designed as an auditable first-pass migration aid, not as an automatic one-click rewrite of an Apache site. Paste a small document-root excerpt, and it processes the text locally in your browser; the input is not sent to Lizely. The result is a fragment for a suitable Nginx server or location context, not a complete nginx.conf. Simple rewrite rules using only the supported flag set can become Nginx lines, while conditions, unfamiliar flags, ambiguous rules, and the no-substitution dash are surfaced with source line numbers instead of being guessed. You still need to compare Apache and Nginx behavior, place each line in the correct block, back up the active configuration, run nginx -t on the assembled file, and test representative requests before reloading. This workflow turns an uncertain text replacement into a reviewable migration process without claiming that per-directory Apache configuration and centralized Nginx configuration are interchangeable.
A deliberately narrow translation scope
Most .htaccess files mix redirects, conditions, access controls, headers, CMS routing, and application-specific rewrites. This converter addresses only a bounded first pass. Its parser handles one line at a time, ignores RewriteEngine On, preserves comments, and emits output only for directives covered by its narrow contract. The result helps inventory straightforward candidates before an engineer reviews them in Nginx.
Processing remains in the browser, and the pasted input is not sent to Lizely. That is a data-handling fact, not a guarantee that every generated directive has the same runtime meaning. The converter cannot access the server, inspect installed modules, discover include order, or execute nginx -t. It supplies review material; the official documentation and the real application architecture determine the final configuration.
Supported rewrite and directive mappings
The supported rewrite form contains an Apache RewriteRule pattern, a substitution, and a bracketed flag list. The automatic flag set is intentionally limited to L, R, R=301, and R=302. These mappings are recognized, but they do not make the surrounding Apache behavior equivalent by themselves.
| Apache construct | Nginx result | Meaning to verify |
|---|---|---|
| [L] | last | Stops the current rewrite processing; placement still matters. |
| [R] | redirect | Creates temporary redirect behavior. |
| [R=301] | permanent | Creates a permanent redirect, which requires extra care because it may be cached. |
| [R=302] | redirect | Creates temporary redirect behavior. |
There is also an important pattern-scope assumption. A pattern in a document-root .htaccess normally matches a path after the directory prefix has been removed, so it often begins with a caret and no slash. An Nginx rewrite pattern sees a URI that begins with a slash. The converter inserts that leading slash for its restricted root-context pattern. This assumption does not extend to nested .htaccess files, Alias mappings, or location-specific Nginx blocks.
| Apache construct | Converter treatment | Migration consideration |
|---|---|---|
| Options -Indexes | autoindex off | Place it in the server or location context where directory listing should be disabled. |
| Local ErrorDocument 404 with a path | error_page 404 using the same path | The supported case is a local 404 document, not an external error destination. |
| Quoted Header set X-Robots-Tag value | An add_header line with the same name and value | Verify the header context and inheritance behavior against the official documentation. |
| Other status codes | Manual migration | Do not infer support from the local 404 mapping. |
| External error documents | Manual migration | The target and Nginx error handling need an explicit design. |
| Conditional headers | Manual migration | The condition cannot be reduced to a safe unconditional header. |
| Environment variables and directive containers | Manual migration | They require rules appropriate to the actual Nginx architecture. |
For the local 404 case, compare the generated line and its context with the Nginx error_page documentation. For the X-Robots-Tag conversion, verify that the name, value, and applicable context match the original intent.
Why some rules become warnings
RewriteCond lines are never translated automatically. Apache conditions can inspect HTTPS state, host names, files, directories, query strings, headers, and captured groups; their evaluation order and server architecture can change the result. When a RewriteRule follows a condition, the converter suppresses that rule too. This avoids emitting an unconditional redirect that could change traffic, create a loop, or expose a route. Warnings retain the original line numbers so you can return to the affected source.
- Unknown flags stop the affected rule. Flags such as QSA, END, F, G, B, and NC are outside the automatic set. The tool returns a warning rather than erasing details that cannot be translated safely.
- A single dash is withheld. The Apache no-substitution target has no safe literal Nginx replacement. It often works with flags that change access or processing without changing the URI, so the warning is part of the result.
- Unsupported constructs stay unsupported. Other status codes, external error documents, conditional headers, environment variables, and directive containers require manual migration.
Warnings are therefore not cosmetic notices. They identify places where an automatic rewrite could change meaning. Resolve each one against the Apache and Nginx documentation rather than dismissing it because an adjacent converted line looks plausible.
Convert and review the excerpt
- Paste a focused document-root .htaccess excerpt. Choose the smallest useful section, especially when the rule is intended to match from the document root. Keep unrelated authentication, CMS, and application logic outside the first conversion pass.
- Review every emitted line and the converted count. Compare each Nginx line with its Apache source line. Check the target path, leading-slash assumption, redirect type, and whether the rule belongs in the server or location context you plan to use.
- Resolve every line-numbered warning manually. Use Apache’s mod_rewrite introduction together with the relevant official Nginx directive documentation. Reconstruct conditions, unsupported flags, and no-substitution behavior deliberately rather than letting a dependent rule become unconditional.
- Merge the reviewed fragment into the correct Nginx context. Place each directive according to its official context and your application’s URL architecture. Keep the assembled file under version control, then back up the active configuration before making an operational change.
- Validate and test before reload. Run nginx -t against the entire assembled configuration, exercise representative requests, and reload only after the results are correct.
Context changes what a valid line means
The converter returns a fragment, not a complete nginx.conf. It does not create an http, server, or location block; choose a listen port; set server_name; configure TLS; locate a document root; preserve PHP routing; forward a proxy; or define logs. Those omissions are deliberate because the converter cannot infer your server design.
Place every reviewed line in the appropriate block according to the official Nginx documentation and the actual application architecture. A line can be syntactically valid yet wrong for its context. The inserted slash is especially important to check because it applies only to the converter’s document-root root-context assumption. For a nested file, Alias, or location-specific rewrite, derive the matching URI and context yourself.
Validate traffic before Nginx serves it
Test the complete configuration, not just the converted fragment. Use staging or a reversible maintenance window when practical, and keep an open recovery session plus the configuration backup available. A failed reload or redirect loop can make a public site unavailable.
For redirect migrations, test old paths, intended new paths, query strings, alternate hosts, and HTTPS behavior. Confirm the response Location header rather than relying only on what appears in the browser address bar. Start with temporary redirects in a controlled environment when practical, then switch to permanent redirects only after the behavior is stable. Browsers and intermediaries may cache permanent redirects, so an incorrect permanent mapping can outlast the configuration change.
For an SEO migration, record which old indexed URLs must reach which destinations so the test inventory covers them. Watch for unintended redirect chains, and keep the original .htaccess beside the reviewed Nginx file in the change record so another engineer can trace each rule back to its source.
Complex Apache logic needs engineering review
Apache and Nginx do not share one request-processing model. Apache discovers .htaccess through directories, and server policy can disable it with AllowOverride. Nginx reads centralized configuration and selects server and location contexts before rewrite processing. Even similar regular expressions can behave differently because the matched string, escaping, query handling, and loop behavior differ.
Treat authentication, authorization, hotlink protection, proxy logic, CMS front-controller rules, and complex conditions as engineering work rather than bulk text replacement. Use the converter as an inventory assistant: one focused excerpt, a reviewed converted count, no unresolved warnings, a context-aware assembled configuration, and a successful validation pass.