Here is a frustration anyone who has used an AI humanizer will recognise. You run a 1,200-word draft. It comes back mostly clean — except for two sentences that still read as machine-written. Your options with most tools are to accept it, edit by hand, or rerun the whole document and pay for 1,200 words again to fix 40.
ClearPen's answer is Spot Fix.
What Is Spot Fix?
Spot Fix is a sentence-level rewrite. After any ClearPen run, every sentence in your result is tinted by its own AI probability. Click a sentence that still reads as AI, choose Spot Fix, and ClearPen:
- Rewrites just that sentence in a focused pass.
- Scores the new version.
- Replaces the sentence in your result, leaving every other sentence exactly as it was.
- Charges the sentence's word count only if the new score is lower than the old one.
A typical Spot Fix finishes in seconds rather than minutes, because only one sentence is processed.
Why "Pay Only If It Improves" Matters
Charging for attempts that did not help is the single most common complaint about AI humanizers. You pay, nothing improves, you pay again.
Spot Fix removes that loop. Its pricing rule is written into the feature: if the rewrite does not lower that sentence's AI probability, no words are used. You can try again on the same sentence, try a different one, or edit by hand — without watching your balance drop for nothing.
It sits alongside ClearPen's other safeguards: no charge for text that already reads as human, and your original returned if a full rewrite would score worse. All of them are described in ClearPen's fair-billing safeguards.
When to Use Spot Fix
Spot Fix is the right tool when:
- The document score is fine but a few sentences are amber or red. Fix those and leave the rest.
- One sentence carries a stock AI pattern — the generic opener, the "In today's fast-paced world" line, the neat closing summary.
- You want to keep everything else exactly as it is. Spot Fix never touches neighbouring sentences.
It is not the right tool for a draft that is red from top to bottom — run the full humanizer for that, or use Deep Clean.
Spot Fix Strength by Plan
| Plan | Spot Fix strength |
|---|---|
| Free | Gentle — the smallest change that keeps your wording closest. |
| Starter, Pro, Power | Max — a stronger rewrite of the chosen sentence. |
Very short fragments (fewer than four words) cannot be Spot Fixed; there is not enough text to rewrite reliably.
What Is Deep Clean?
Some text is stubborn. Dense technical prose, formulaic business writing and very generic AI output can resist the standard rewriting passes. When ClearPen's internal quality bar is not met after its usual escalation, the result comes back marked as a best-effort result — and ClearPen offers Deep Clean.
Deep Clean reruns the document with up to three times more rewriting attempts in parallel, then keeps the best one. It takes longer than a standard run and uses the same word count as the original run. Deep Clean is included on Pro and Power plans.
Spot Fix vs. Deep Clean vs. Rerunning
| Spot Fix | Deep Clean | Rerun the whole document | |
|---|---|---|---|
| Scope | One sentence | Whole document | Whole document |
| Best for | A few flagged sentences in a good result | Text that resists standard passes | Starting over with different settings |
| Words used | That sentence, only if it improves | Document word count | Document word count |
| Changes other sentences? | No | Yes | Yes |
| Plans | All | Pro, Power | All |
Fix only what needs fixing
Run a draft, open the sentence heatmap, and Spot Fix anything that still stands out. Free plan, no credit card.
Related Reading
Frequently asked questions
- What is Spot Fix in ClearPen?
- Spot Fix rewrites a single sentence you select from ClearPen's sentence heatmap, re-scores the new version, and replaces the sentence in your result. The rest of your text is untouched.
- How much does Spot Fix cost?
- Spot Fix uses only the word count of the sentence being rewritten, and only if the new version scores lower than the original sentence. If the score does not improve, nothing is charged.
- Is Spot Fix available on the free plan?
- Yes. On the free plan Spot Fix rewrites at Gentle strength; on paid plans it rewrites at Max strength for a stronger change.
- What is Deep Clean?
- Deep Clean is a rerun mode for text that resists ClearPen's standard passes. It runs up to three times more rewriting attempts in parallel and keeps the best one. It is offered when a result comes back as a best-effort fallback and is included on Pro and Power plans.
- Why rewrite one sentence instead of the whole document?
- Because most flagged text is mostly fine with a few telltale sentences. Rerunning the whole document costs the full word count again and can change sentences that were already good. Spot Fix targets only the problem and only charges when it helps.