Load your own discs — US Disc 1 (the patch target), optionally the JP disc (retranslation source) and the gadesx Spanish patch (ground truth / reference). Edit dialogue boxes with a live byte budget, then export an in-place write, a PPF3 patch or an xdelta. Everything happens in your browser.
Both US discs carry the same script file (STGEVT.BIN is byte-identical
across disc 1 and 2, verified at the sector level) — so a patch applied to only one disc
leaves the other running the original text. Load both and the exporter emits a patch for
each. The same holds for JP: either JP disc supplies the identical source script.