The impossible synonym you pick tells readers why something cannot happen. Is the goal out of reach? Call it unachievable or hopeless. Is the request refused? Say it is out of the question. Is the story hard to swallow? Call it far-fetched or inconceivable. Is the problem too big to get past? It is insurmountable.
English speakers also say impossible when they only mean very hard, so this page separates true impossibility from exaggeration. For the positive side, see possible synonyms.
Swatch at a glance
Best swaps
unachievable, hopeless, unworkable, out of the question, unthinkablePart of speech
Adjective (noun impossibility, adverb impossibly)Most formal
impracticable, insurmountable, inconceivableMost casual
no way, not a chance, a lost causeStrongest
inconceivable, unthinkableAntonyms
possible, achievable, feasible, doableWatch out
Impractical means possible but not sensible. Impracticable means it cannot be done in practice.
Pick an impossible synonym by reason
Ask why the thing cannot happen, then choose from that row.
| Reason | Words | Example |
|---|---|---|
| Too far beyond your means | unachievable, unattainable, out of reach | A two-hour marathon is out of reach for most runners. |
| The plan cannot work | unworkable, not feasible, impracticable | The timetable proved unworkable. |
| Someone will not allow it | out of the question, off the table | A pay raise is off the table this round. |
| Hard to believe | far-fetched, implausible, absurd | His excuse sounded far-fetched. |
| Too big to overcome | insurmountable, insoluble | The debt looked insurmountable. |
| A person who will not cooperate | unreasonable, exasperating | The landlord was being unreasonable. |
Unrealistic up to inconceivable
The chip strip ranks how firmly the door is shut. Unrealistic says the plan ignores the facts but leaves room to argue. Not feasible is the measured business verdict. Hopeless adds discouragement. Unachievable is a firm, practical no. Inconceivable means the mind cannot even picture it.
In work writing, the lower rungs are often more honest. Telling a client a deadline is unrealistic invites a talk about options, while impossible ends the talk.
When you really mean very hard
People say impossible about tasks that are only tough: the exam was impossible, this jar is impossible to open. In careful writing, pick a word that admits the effort.
- The exam was impossible becomes the exam was brutally hard.
- This knot is impossible becomes this knot is stubborn.
- Finding parking downtown is impossible becomes finding parking downtown is a nightmare.
For more options, see difficult synonyms and challenging synonyms.
More sentence makeovers
- That goal is impossible becomes that goal is unattainable with our budget.
- A refund is impossible becomes a refund is not an option.
- It is impossible to believe becomes it is hard to believe or it is inconceivable.
- An impossible situation becomes a hopeless situation or a no-win situation.
- My little brother is impossible today becomes my little brother is impossible to reason with today, or simply exasperating.
A project update first said: "Launching by Friday is impossible." The manager rewrote it: "Launching by Friday is not feasible without cutting testing. A Tuesday launch is realistic." The new version explains the limit and offers a path, which is what readers of a status email need.
Phrases and idioms with the same idea
Everyday speech is full of vivid ways to declare that something will never happen: not a chance, no way, a lost cause, a pipe dream, when pigs fly and not in a million years. A tall order is softer and means very hard but possible. Easier said than done also admits that a thing can be done.
Idioms like when pigs fly are playful. Keep them out of formal reports and cover letters.
Antonyms of impossible
The plain opposite is possible. For goals, use achievable, attainable or realistic. For plans, use feasible or workable. In conversation, doable is friendly and common.
- With two more staff, the target is achievable.
- Ten pages by Monday is doable.
Find more adjectives in the describing words hub, or check likely synonyms for words about chance.
Frequently asked questions
Are there dressier alternatives to impossible for reports?
Impracticable, unattainable and insurmountable suit formal writing. Not feasible is common in business reports and sounds measured.
What do I call an impossible goal on a resume?
Avoid the word and show the result instead: met a target others called unrealistic. Words like ambitious or stretch goal sound positive.
Is unbelievable a synonym for impossible?
Only when you mean a claim cannot be true. Unbelievable is also used as praise, as in an unbelievable goal, so make sure your context points to doubt rather than delight.
How do friends say impossible in relaxed chat?
No way, not a chance and not in a million years are relaxed. A lost cause works when people have already tried and failed.
How is impractical different from impossible?
Impractical means it could be done but would be a bad idea, such as white carpet in a muddy house. Impossible rules the thing out entirely.
Which antonym of impossible should I reach for?
Possible is the direct antonym. Achievable, feasible and doable help when your aim is to sound encouraging.