In conclusion, is a phrase that is commonly used to summarize the main points of an essay or argument. However, if one wishes to add some variety to their writing, there are several synonyms that can replace "in conclusion".
To begin, "in summary" is a great replacement for "in conclusion". This phrase succinctly encapsulates the main points of the essay or argument in a few simple words. Similarly, "in short" provides the same level of summarization, but with a more concise meaning.
Another option is to use a phrase such as "in closing". This phrase is much less common than the former two and has a more formal feel to it. This makes it an excellent choice for more serious and scholarly essays. One could also use phrases such as "ultimately", "all things considered" or "in the final analysis" for a similar effect.
Finally, for a more creative approach, one could use phrases such as "on the whole", "to sum up", "to wrap up", or "as can be seen". These phrases are more poetic and can add some flair to an essay.
In conclusion, there are many different phrases that can be used to replace "in conclusion" in an essay. Whether one wishes to use a more formal phrase or a more creative one, there are many options available.