On Tue, Feb 10, 2026 at 6:46 PM 'Sam Clegg' via emscripten-discuss < [email protected]> wrote:
> Ah, was your original question about the runtimes we support when > generating code? If so, then I misunderstood. > No, it wasn't. I simply found the MIN_X_VERSION options between asking the original question, and my reply to you. > We don't have any official or hard-and-rules about how far back we go on > browser/engine support, but we do go back a very long way. When you opt > into older browser support via MIN_XXX_VERSION (or using > `LEGACY_VM_SUPPORT` which sets all the `MIN_XXX_VERSION` to their minimum > values) that does indeed effec the generated code. The idea is that the > generated code will not contains new JS or Wasm features. In some cases we > run lowering passes on the Wasm file and for older JS engines we run babel > on the output to transpile to ES5. > I'm not intending to try to reach back a long way. I'm porting a big mathematical modelling library to WASM, and I am quite happy for it to require fairly recent browsers and run-times. I hadn't expected Emscripten to track all the features described in https://github.com/emscripten-core/emscripten/blob/83df45fc083ef0560e5a5b0f4108195f1f07c859/tools/feature_matrix.py, but I'm happy that it does. Thanks, John For the current set of minimum values see the documentation for each of the > `MIN_XXX_VERSION` settings. e.g. > https://emscripten.org/docs/tools_reference/settings_reference.html#min-chrome-version. > Here you can see we support chrome versions going back to Chrome 74 which > is ~6 years old now. You can also see all the minimum version here: > https://github.com/emscripten-core/emscripten/blob/83df45fc083ef0560e5a5b0f4108195f1f07c859/tools/feature_matrix.py#L25-L30 > > See https://github.com/emscripten-core/emscripten/issues/20601 for a very > old but ongoing discussion about creating some kind of official policy: > https://github.com/emscripten-core/emscripten/issues/20601 > > cheers, > sam > > > > > On Tue, Feb 10, 2026 at 9:19 AM John Dallman <[email protected]> > wrote: > >> Thanks for that. I've found the MIN_$RUNTIME_VERSION set of options; do >> those simply do a run-time version check so that a program can refuse to >> run on something it doesn't want to support, or do they affect wasm code >> generation? >> >> Thanks, >> >> John >> >> On Mon, Feb 9, 2026 at 10:59 PM 'Sam Clegg' via emscripten-discuss < >> [email protected]> wrote: >> >>> I don't believe we have such I'm afraid. >>> >>> Note that emscripten does rolling releases, always cut from the main >>> branch. We don't (or rather we have never done) any kind of branching or >>> patching of existing releases. So while we support our users no matter >>> what version they are using, if you need a specific fix we always recommend >>> upgrading the latest version. You could, of course, backport patches >>> yourself, but we never do this officially/upstream. >>> >>> cheers, >>> sam >>> >>> >>> >>> >>> >>> On Mon, Feb 9, 2026 at 4:51 AM John Dallman <[email protected]> >>> wrote: >>> >>>> I haven't found one via web searching. >>>> >>>> Thanks, >>>> >>>> John >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "emscripten-discuss" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion visit >>>> https://groups.google.com/d/msgid/emscripten-discuss/CAH1xqg%3Dc4B1DCQOKEfJL84qLOrNu20pKXArgddZKoOHu8sqRkg%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/emscripten-discuss/CAH1xqg%3Dc4B1DCQOKEfJL84qLOrNu20pKXArgddZKoOHu8sqRkg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "emscripten-discuss" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion visit >>> https://groups.google.com/d/msgid/emscripten-discuss/CAL_va2-RsDLTk4f-mbKqtM1cVdzEaqFtpNCydcuMaaEWYLdFMQ%40mail.gmail.com >>> <https://groups.google.com/d/msgid/emscripten-discuss/CAL_va2-RsDLTk4f-mbKqtM1cVdzEaqFtpNCydcuMaaEWYLdFMQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "emscripten-discuss" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/d/msgid/emscripten-discuss/CAH1xqg%3DRYh0JvtD_EeqQ7TXCik-qsniOFtiLnLgX%3DV856A5kBA%40mail.gmail.com >> <https://groups.google.com/d/msgid/emscripten-discuss/CAH1xqg%3DRYh0JvtD_EeqQ7TXCik-qsniOFtiLnLgX%3DV856A5kBA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/emscripten-discuss/CAL_va28RjLa3Bqr5JXfWvEbXEQ6aOiw1HXp9x-sHVW3%2BXia1GQ%40mail.gmail.com > <https://groups.google.com/d/msgid/emscripten-discuss/CAL_va28RjLa3Bqr5JXfWvEbXEQ6aOiw1HXp9x-sHVW3%2BXia1GQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. 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