Prompt Redundancy Remover

Find and merge duplicate instructions in long system prompts

Scans a long system prompt for semantically redundant sentences using TF-IDF cosine similarity computed entirely in your browser, highlights near-duplicate pairs, and helps you cut repeated instructions to save tokens. It runs free in your browser on Gera Tools, with nothing uploaded.

Last updated Source: Gera Tools

How does it detect redundancy without an AI model?

It uses TF-IDF cosine similarity. Each sentence becomes a weighted vector of its words; pairs whose vectors point in nearly the same direction are flagged as overlapping. It is fully deterministic and runs in your browser with no network calls.

Prompt redundancy remover

Long system prompts accumulate cruft. You add a rule, then three edits later you add nearly the same rule again in different words. Every duplicate sentence costs tokens on every single call and can even confuse the model with conflicting phrasings. This tool scans your prompt for sentence pairs that say the same thing and flags them so you can cut the bloat.

Why redundancy creeps in

Prompt redundancy is almost never intentional. It is a natural consequence of iterative development: you write a set of instructions, test them, discover an edge case, add a new sentence to handle it — and that sentence partially overlaps with an earlier one you forgot about. Repeat this cycle a dozen times and you have a 1,200-token prompt that could be 700 tokens without losing any actual instruction.

The other source is copy-paste. Many prompts are built from components — a tone section, a format section, a domain-specific rules section — assembled from earlier prompts or templates. The same instruction may appear in slightly different wording in two sections that were never edited in relation to each other.

Redundancy has two costs beyond tokens: it makes prompts harder to read and maintain, and it occasionally confuses models with subtly different phrasings of what should be one rule. “Always respond formally” and “Use a professional, formal register in all responses” carry the same meaning, but a model that finds a slight contradiction between two paraphrases may behave unpredictably.

How it works

The tool splits your prompt into sentences and converts each one into a TF-IDF vector — a weighted bag of words where common, uninformative words count for little and distinctive words count for more. It then computes the cosine similarity between every pair of sentences. Pairs above your threshold point in nearly the same direction in word space, which means they share most of their meaningful vocabulary — the signature of a restated instruction. Everything runs locally; your prompt never leaves the page.

Tips and notes

  • Tune the threshold. 0.6 is a good start. Raise it toward 0.8 if you get too many loose matches; lower it to surface softer paraphrases.
  • TF-IDF is lexical, not semantic. It catches “always respond in JSON” vs “your responses must always be JSON” but will miss two sentences that mean the same thing with zero shared words. That is the documented limitation.
  • Keep intentional repetition. Repeating a hard safety rule on purpose is fine — only remove accidental duplication.
  • Re-run after editing. Trim a pair, paste the result back, and scan again to catch second-order overlaps the first pass hid.
  • Start with long prompts. On short prompts the tool may flag pairs that look similar simply because few distinctive words are available; it is most valuable on prompts over 500 tokens where cruft genuinely compounds.